Publications
All peer reviewed publications are listed below.
Displaying page 5 of 24.
Quantification of biological aging in young adults | 2015
Belsky, D.W., Caspi, A., Houts,
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PNAS (Proceedings of the National Academy of Sciences of the USA) , 2015, 112(30), E4104-E4110.
https://doi.org/10.1073/pnas.1506264112
Link to full publication »
Our ref: RO669
Antiaging therapies show promise in model organism research. Translation to humans is needed to address the challenges of an aging global population. Interventions to slow human aging will need to be applied to still-young individuals. However, most human aging research examines older adults, many with chronic disease. As a result, little is known about aging in young humans. We studied aging in 954 young humans, the Dunedin Study birth cohort, tracking multiple biomarkers across three time points spanning their third and fourth decades of life. We developed and validated two methods by which aging can be measured in young adults, one cross-sectional and one longitudinal. Our longitudinal measure allows quantification of the pace of coordinated physiological deterioration across multiple organ systems (e.g., pulmonary, periodontal, cardiovascular, renal, hepatic, and immune function). We applied these methods to assess biological aging in young humans who had not yet developed age-related diseases. Young individuals of the same chronological age varied in their “biological aging” (declining integrity of multiple organ systems). Already, before midlife, individuals who were aging more rapidly were less physically able, showed cognitive decline and brain aging, self-reported worse health, and looked older. Measured biological aging in young adults can be used to identify causes of aging and evaluate rejuvenation therapies.
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Early-life intelligence predicts midlife biological age | 2015
Schaefer, J., Caspi, A., Belsky,
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Journal of Gerontology, Series B: Psychological Sciences and Social Sciences, 2015, First published online May 26, 2015, doi: 10.1093/geronb/gbv035.
doi:10.1093/geronb/gbv035
Link to full publication »
Our ref: RO668
Objectives. Early-life intelligence has been shown to predict multiple causes of death in populations around the world. This finding suggests that intelligence might influence mortality through its effects on a general process of physiological deterioration (i.e., individual variation in 'biological age'). We examined whether intelligence could predict measures of aging at midlife before the onset of most age-related disease. Methods. We tested whether intelligence assessed in early childhood, middle childhood, and midlife predicted midlife biological age in members of the Dunedin Study, a population-representative birth cohort. Results. Lower intelligence predicted more advanced biological age at midlife as captured by perceived facial age, a 10-biomarker algorithm based on data from the National Health and Nutrition Examination Survey (NHANES), and Framingham heart age (r = 0.1–0.2). Correlations between intelligence and telomere length were less consistent. The associations between intelligence and biological age were not explained by differences in childhood health or parental socioeconomic status, and intelligence remained a significant predictor of biological age even when intelligence was assessed before Study members began their formal schooling. Discussion. These results suggest that accelerated aging may serve as one of the factors linking low early-life intelligence to increased rates of morbidity and mortality.
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Is adult ADHD a childhood-onset neurodevelopmental disorder? Evidence from a four-decade longitudinal cohort study. | 2015
Moffitt, T.E., Houts, R., Asherson,
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American Journal of Psychiatry, 2015, .
Link to full publication »
Our ref: RO667
Objective: Despite a prevailing assumption that adult ADHD is a childhood-onset neurodevelopmental disorder, no prospective longitudinal study has described the childhoods of the adult ADHD population. The authors report follow-back analyses of ADHD cases diagnosed in adulthood, alongside follow-forward analyses of ADHD cases diagnosed in childhood, in one cohort. Method: Participants belonged to a representative birth cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972 and 1973 and followed to age 38, with 95% retention. Symptoms of ADHD, associated clinical features, comorbid disorders, neuropsychological deficits, genome-wide association study-derived polygenic risk, and life impairment indicators were assessed. Data sources were participants, parents, teachers, informants, neuropsychological test results, and administrative records. Adult ADHD diagnoses used DSM-5 criteria, apart from onset age and cross-setting corroboration, which were study outcome measures. Results: As expected, childhood ADHD had a prevalence of 6% (predominantly male) and was associated with childhood comorbid disorders, neurocognitive deficits, polygenic risk, and residual adult life impairment. Also as expected, adult ADHD had a prevalence of 3% (gender balanced) and was associated with adult substance dependence, adult life impairment, and treatment contact. Unexpectedly, the childhood ADHD and adult ADHD groups comprised virtually nonoverlapping sets; 90% of adult ADHD cases lacked a history of childhood ADHD. Also unexpectedly, the adult ADHD group did not show tested neuropsychological deficits in childhood or adulthood, nor did they show polygenic risk for childhood ADHD.
Conclusions: The findings raise the possibility that adults presenting with the ADHD symptom picture may not have a childhood-onset neurodevelopmental disorder. If this finding is replicated, then the disorder’s place in the classification system must be reconsidered, and research must investigate the etiology of adult ADHD.
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Cardiorespiratory fitness and cognitive function at midlife: Neuroprotection or Neuroselection? | 2015
Belsky, D.W., Caspi, A., Israel,
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Annals of Neurology, 2015, 77(4), 607-617.
Link to full publication »
Our ref: RO666
Objective: A study was undertaken to determine whether better cognitive functioning at midlife among more physically fit individuals reflects neuroprotection, by which fitness protects against age-related cognitive decline, or neuroselection, by which children with higher cognitive functioning select more active lifestyles. Methods: Children in the Dunedin Longitudinal Study (N?=?1,037) completed the Wechsler Intelligence Scales and the Trail Making, Rey Delayed Recall, and Grooved Pegboard tasks as children and again at midlife (age?=?38 years). Adult cardiorespiratory fitness was assessed using a submaximal exercise test to estimate maximum oxygen consumption adjusted for body weight in milliliters/minute/kilogram. We tested whether more fit individuals had better cognitive functioning than their less fit counterparts (which could be consistent with neuroprotection), and whether better childhood cognitive functioning predisposed to better adult cardiorespiratory fitness (neuroselection). Finally, we examined possible mechanisms of neuroselection. Results: Participants with better cardiorespiratory fitness had higher cognitive test scores at midlife. However, fitness-associated advantages in cognitive functioning were already present in childhood. After accounting for childhood baseline performance on the same cognitive tests, there was no association between cardiorespiratory fitness and midlife cognitive functioning. Socioeconomic and health advantages in childhood and healthier lifestyles during young adulthood explained most of the association between childhood cognitive functioning and adult cardiorespiratory fitness. Interpretation: We found no evidence for a neuroprotective effect of cardiorespiratory fitness as of midlife. Instead, children with better cognitive functioning are selecting healthier lives. Fitness interventions may enhance cognitive functioning. However, observational and experimental studies testing neuroprotective effects of physical fitness should consider confounding by neuroselection.
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Effects of quitting cannabis on respiratory symptoms | 2015
Hancox, R. J., Shin, H.H., Gray,
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European Respiratory Journal, 2015, .
doi: 10.1183/09031936.00228914
Our ref: RO665
Smoking cannabis is associated with symptoms of bronchitis. Little is known about the persistence of symptoms after stopping cannabis use. We assessed associations between changes in cannabis use and respiratory symptoms in a population-based cohort of 1037 young adults. Participants were asked about cannabis and tobacco use at ages 18, 21, 26, 32 and 38 years. Symptoms of morning cough, sputum production, wheeze, dyspnoea on exertion and asthma diagnoses were ascertained at the same ages. Frequent cannabis use was defined as .52 occasions over the previous year. Associations between frequent cannabis use and respiratory symptoms were analysed using generalised estimating equations with adjustments for tobacco smoking, asthma, sex and age. Frequent cannabis use was associated with morning cough (OR 1.97, p<0.001), sputum production (OR 2.31, p<0.001) and wheeze (OR 1.55, p<0.001). Reducing or quitting cannabis use was associated with reductions in the prevalence of cough, sputum and wheeze to levels similar to nonusers. Frequent cannabis use is associated with symptoms of bronchitis in young adults. Reducing cannabis use often leads to a resolution of these symptoms.
Media Report:
http://www.dailymail.co.uk/health/article-3087876/How-cannabis-wrecks-lungs-ONE-joint-week-likely-suffer-breathing-problems-smoke-regular-tobacco.html
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The Dunedin Multidisciplinary Health and Development Study: Overview of the first 40 years, with an eye to the future | 2015
Poulton, R. , Moffitt, T.E., Silva,
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Social Psychiatry and Psychiatric Epidemiology , 2015, 50(5), 679-693.
DOI 10.1007/s00127-015-1048-8
Our ref: RO664
The Dunedin Multidisciplinary Health and Development Study began more than four decades ago. Unusual at the time, it was founded as a multidisciplinary research enterprise, and was strongly supported by the Dunedin community, both professional and lay, in its early years. Seven research themes have evolved over the last 40 years focusing on: mental and neuro-cognition, cardiovascular risk, respiratory health, oral health, sexual and reproductive health and psychosocial functioning. A seventh, more applied theme, seeks to maximise the value of the Study findings for New Zealand’s indigenous people Mâori (or tangata whenua transl people of the land). The Study has published over 1200 papers and reports to date, with almost 2/3 of these being in peer reviewed journals. Here we provide an overview of the study, its history, leadership structure, scientific approach, operational foci, and some recent examples of work that illustrates: (i) the value of multidisciplinary data; (ii) how the Study is well positioned to addresses contemporary issues; and (iii) how research can simultaneously address multiple audiences - from researchers and theoreticians to policy makers and practitioners. Near future research plans are described, and we end by reflecting upon the core aspects of the Study that portend future useful contributions.
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Inconsistency in Reporting Abstention and Heavy Drinking Frequency: Associations with Sex and Socioeconomic Status, and Potential Impacts | 2015
Kydd, R.M., Connor, J.
Alcohol and Alcoholism, 2015, 50(3), 333-345.
doi: 10.1093/alcalc/agu106
Link to full publication »
Our ref: RO663
Aims: To describe inconsistencies in reporting past-year drinking status and heavy drinking occasions (HDOs) on single questions from two different instruments, and to identify associated characteristics and impacts. Methods: We compared computer-presented Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) with categorical response options, and mental health interview (MHI) with open-ended consumption questions, completed on the same day. Participants were 464 men and 459 women aged 38 (91.7% of surviving birth cohort members). Differences in dichotomous single-item measures of abstention and HDO frequency, associations of inconsistent reporting with sex, socioeconomic status (SES) and survey order, and impacts of instrument choice on associations of alcohol with sex and SES were examined. Results: The AUDIT-C drinking frequency question estimated higher past-year abstention prevalence (AUDIT = 7.6%, MHI = 5.4%), with one-third of AUDIT-C abstainers being MHI drinkers. Only AUDIT-C produced significant sex differences in abstainer prevalence. Inconsistencies in HDO classifications were bidirectional, but with fewer HDOs reported on the MHI than AUDIT-C question. Lower SES was associated with inconsistency in abstention and weekly+ HDOs. Abstention and higher HDO frequency were associated with lower SES overall, but sex-specific associations differed by instrument. Conclusions: In this context, data collection method affected findings, with inconsistencies in abstention reports having most impact. Future studies should: (a) confirm self-reported abstention; (b) consider piloting data collection methods in target populations; (c) expect impacts of sex and SES on measurements and analyses.
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Cumulative incidence of infertility in a New Zealand birth cohort to age 38 by sex, and the relationship with family formation | 2015
van Roode, T., Dickson, N., Righarts,
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Fertility and Sterility, 2015, Available online first 27 January 2015, http://dx.doi.org/10.1016/j.fertnstert.2014.12.121.
http://www.sciencedirect.com/science/article/pii/S0015028214025527
Our ref: RO662
Objective: To estimate the cumulative incidence of infertility for men and women in a population-based sample. Design: Longitudinal study of a birth cohort. Setting: Research unit. A population-based birth cohort of 1,037 men and women born in Dunedin, New Zealand, between 1972 and1973. Main Outcome Measure(s): Cumulative incidence of infertility by age 32 and 38, distribution of causes and service use for infertility, live birth subsequent to infertility, and live birth by age38. Result(s): The cumulative incidence of infertility by age 38 ranged from 14.4% to 21.8% for men and from 15.2% to 26.0% for women depending on the infertility definition and data used. Infertility, defined as having tried to conceive for 12months or more or having sought medical help to conceive, was experienced by 21.8% (95% confidence interval [CI], 17.726.2) of men and 26.0% (95% CI, 21.830.6) of women by age 38. For those who experienced infertility, 59.8% (95% CI, 48.370.4) of men and 71.8% (95% CI, 62.180.3) of women eventually had a live birth. Successful resolution of infertility and entry into parenthood by age 38 were much lower for those who first experienced infertility in their mid to late thirties compared with at a younger age. Conclusion(s): Comparison of reports from two assessments in this cohort study suggests infertility estimates from a single cross-sectional study may underestimate lifetime infertility. The lower rate of resolution and entry into parenthood for those first experiencing infertility in their mid to late thirties highlights the consequences of postponing parenthood and could result in involuntary childlessness and fewer children than desired.
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Social Jetlag, Obesity and Metabolic Disorder: Investigation in a Cohort Study | 2015
Parsons, M.J., Moffitt, T.E., Gregory,
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International Journal of Obesity, 2015, Advance online publication 20 January 2015; doi: 10.1038/ijo.2014.201.
http://www.nature.com/ijo/journal/vaop/ncurrent/full/ijo2014201a.html
Our ref: RO661
Background: Obesity is one of the leading causes of preventable death worldwide. Circadian rhythms are known to control both sleep timing and energy homeostasis, and disruptions in circadian rhythms have been linked with metabolic dysfunction and obesity-associated disease. In previous research, social jetlag, a measure of chronic circadian disruption caused by the discrepancy between our internal versus social clocks, was associated with elevated self-reported body mass index, possibly indicative of a more generalized association with obesity and metabolic dysfunction. Methods: We studied participants from the population-representative Dunedin Longitudinal Study (N=1037) to determine whether social jetlag was associated with clinically assessed measurements of metabolic phenotypes and disease indicators for obesity-related disease, specifically, indicators of inflammation and diabetes. Results: Our analysis was restricted to N=815 non-shift workers in our cohort. Among these participants, we found that social jetlag was associated with numerous clinically assessed measures of metabolic dysfunction and obesity. We distinguished between obese individuals who were metabolically healthy versus unhealthy, and found higher social jetlag levels in metabolically unhealthy obese individuals. Among metabolically unhealthy obese individuals, social jetlag was additionally associated with elevated glycated hemoglobin and an indicator of inflammation. Conclusions: The findings are consistent with the possibility that ‘living against our internal clock’ may contribute to metabolic dysfunction and its consequences. Further research aimed at understanding that the physiology and social features of social jetlag may inform obesity prevention and have ramifications for policies and practices that contribute to increased social jetlag, such as work schedules and daylight savings time.
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Community water fluoridation and intelligence: Prospective Study in New Zealand | 2015
Broadbent, J. M. , Thomson, W. M., Ramrakha,
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American Journal of Public Health, 2015, 105(1), 72-76.
https://doi.org/10.2105/AJPH.2013.301857
Link to full publication »
Our ref: RO653
Objectives.This study aimed to clarify the relationship between community water fluoridation (CWF) and IQ. Methods. We conducted a prospective study of a general population sample of those born in Dunedin, New Zealand, between April 1, 1972, and March 30, 1973 (95.4% retention of cohort after 38 years of prospective follow-up). Residence in a CWF area, use of fluoride dentifrice and intake of 0.5-milligram fluoride tablets were assessed in early life (prior to age 5 years); we assessed IQ repeatedly between ages 7 to 13 years and at age 38 years. Results. No significant differences in IQ because of fluoride exposure were noted. These findings held after adjusting for potential confounding variables, including sex, socioeconomic status, breastfeeding, and birth weight (as well as educational attainment for adult IQ outcomes). Conclusions. These findings do not support the assertion that fluoride in the context of CWF programs is neurotoxic. Associations between very high fluoride exposure and low IQ reported in previous studies may have been affected by confounding, particularly by urban or rural status.
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Mental health antecedents of early midlife insomnia: Evidence from a four-decade longitudinal study | 2014
Goldman-Mellor, S., Gregory, A. M., Caspi,
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Sleep, 2014, 37(11), 1767-1775.
https://doi.org/10.1038/mp.2012.72
Link to full publication »
Our ref: RO660
Study objectives. Insomnia is a highly prevalent condition that constitutes a major public health and economic burden. However, little is known about the developmental etiology of adulthood insomnia. Design. We examined whether indicators of psychological vulnerability across multiple developmental periods (psychiatric diagnoses in young adulthood and adolescence, childhood behavioral problems, and familial psychiatric history) predicted subsequent insomnia in adulthood. Setting and participants. We used data from the ongoing Dunedin Multidisciplinary Health and Development Study, a population-representative birth cohort study of 1,037 children in New Zealand who were followed prospectively from birth (19721973) through their fourth decade of life with a 95% retention rate. Measurements. Insomnia was diagnosed at age 38 according to DSM-IV criteria. Psychiatric diagnoses, behavioral problems, and family psychiatric histories were assessed between ages 5 and 38. Results. In cross-sectional analyses, insomnia was highly comorbid with multiple psychiatric disorders. After controlling for this concurrent comorbidity, our results showed that individuals who have family histories of depression or anxiety, and who manifest lifelong depression and anxiety beginning in childhood, are at uniquely high risk of age-38 insomnia. Other disorders did not predict adulthood insomnia. Conclusions. The link between lifelong depression and anxiety symptoms and adulthood insomnia calls for further studies to clarify the neurophysiological systems or behavioral conditioning processes that may underlie this association.
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Perinatal Complications and Aging Indicators by Midlife | 2014
Shalev, I., Caspi, A., Ambler,
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Pediatrics, 2014, 134 e1315-e1323. Available early view online DOI: 10.1542/peds.2014-1669.
http://pediatrics.aappublications.org/content/early/2014/10/21/peds.2014-1669
Our ref: RO658
BACKGROUND: Perinatal complications predict increased risk for morbidity and early mortality. Evidence of perinatal programming of adult mortality raises the question of what mechanisms embed this long-term effect. We tested a hypothesis related to the theory of developmental origins of health and disease: that perinatal complications assessed at birth predict indicators of accelerated aging by midlife. METHODS: Perinatal complications, including both maternal and neonatal complications, were assessed in the Dunedin Multidisciplinary Health and Development Study cohort (N = 1037), a 38-year, prospective longitudinal study of a representative birth cohort. Two aging indicators were assessed at age 38 years, objectively by leukocyte telomere length (TL) and subjectively by perceived facial age. RESULTS: Perinatal complications predicted both leukocyte TL (b =20.101; 95% confidence interval, 20.169 to 20.033; P = .004) and perceived age (b = 0.097; 95% confidence interval, 0.029 to 0.165; P = .005) by midlife. We repeated analyses with controls for measures of family history and social risk that could predispose to perinatal complications and accelerated aging, and for measures of poor health taken in between birth and the age-38 follow-up. These covariates attenuated, but did not fully explain the associations observed between perinatal complications and aging indicators. CONCLUSIONS: Our findings provide support for early-life developmental programming by linking newborns’ perinatal complications to accelerated aging at midlife. We observed indications of accelerated aging “inside,” as measured by leukocyte TL, an indicator of cellular aging, and “outside,” as measured by perceived age, an indicator of declining tissue integrity. A better understanding of mechanisms underlying perinatal programming of adult aging is needed.
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Credit Scores, Cardiovascular Disease Risk and Human Capital | 2014
Israel, S., Caspi, A., Belsky,
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PNAS, 2014, Available Early Edition online DOI: 10.1073.
doi/10.1073/pnas.1409794111
Link to full publication »
Our ref: RO659
Credit scores are the most widely used instruments to assess whether or not a person is a financial risk. Credit scoring has been so successful that it has expanded beyond lending and into our everyday lives, even to inform how insurers evaluate our health. The pervasive application of credit scoring has outpaced knowledge about why credit scores are such useful indicators of individual behavior. Here we test if the same factors that lead to poor credit scores also lead to poor health. Following the Dunedin (New Zealand) Longitudinal Study cohort of 1,037 study members, we examined the association between credit scores and cardiovascular disease risk and the underlying factors that account for this association. We find that credit scores are negatively correlated with cardiovascular disease risk. Variation in household income was not sufficient to account for this association. Rather, individual differences in human capital factors educational attainment, cognitive ability, and self-control predicted both credit scores and cardiovascular disease risk and accounted for ~45% of the correlation between credit scores and cardiovascular disease risk. Tracing human capital factors back to their childhood antecedents revealed that the characteristic attitudes, behaviors, and competencies children develop in their first decade of life account for a significant portion (~22%) of the link between credit scores and cardiovascular disease risk at midlife. We discuss the implications of these findings for policy debates about data privacy, financial literacy, and early childhood interventions.
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Prevalence and correlates of a 'knee' pattern on the maximal expiratory flow volume loop in young adults | 2014
Shin, H.H., Sears, M.R., Hancox,
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Respirology, 2014, 19(7), 1052-1058.
http://onlinelibrary.wiley.com/doi/10.1111/resp.12352/pdf
Our ref: RO657
Background and objective: Visual inspection of the maximal flow-volume curve is an important step in interpreting spirometry. Many young people have a convex inflection or 'knee' on the expiratory part of the loop. This is thought to be a normal variant, but this view is based on theoretical grounds, and the epidemiology of the knee pattern has never been reported. Methods: Flow-volume loops from an unselected birth cohort of 1037 individuals at ages 18, 26, 32 and 38 years were visually inspected for a knee pattern. Associations with asthma diagnoses, smoking history, body mass index (BMI) and spirometry were assessed. Results: The knee pattern was found in approximately two thirds of men and women at age 18. The prevalence decreased with age, but it was more likely to persist in women. The knee was more common after bronchodilator and was associated with higher forced expiratory volume in 1 s/forced vital capacity ratios and mid-expiratory flow rates. There was no association with smoking, except for an inverse correlation in men at age 18. No association was found with BMI. Women with asthma were less likely to have a knee at both ages 18 and 38, whereas men with asthma showed an inverse association at age 18. Conclusions: A knee is a very common pattern on flow-volume loop in young adults. In accordance with theoretical predictions, the prevalence of the knee declines with age, but it is more likely to persist in women. It is associated with less airflow obstruction and is less common in people with asthma.
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Is Chronic Asthma Associated with Shorter Leukocyte Telomere Length at Midlife? | 2014
Belsky, D.W., Shalev, I., Sears,
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American Journal of Respiratory and Critical Care Medicine, 2014, First published online 23 Jun 2014 as DOI: 10.1164/rccm.201402-0370OC.
http://www.atsjournals.org/doi/abs/10.1164/rccm.201402-0370OC#.U7NrU1NsHk8
Link to full publication »
Our ref: RO656
Background. Asthma is prospectively associated with age-related chronic diseases and mortality, suggesting the hypothesis that asthma may relate to a general, multi-system phenotype of accelerated aging. Objective. To test whether chronic asthma is associated with a proposed biomarker of accelerated aging, leukocyte telomere length. Method. Asthma was ascertained prospectively in the Dunedin Multidisciplinary Health and Development Study cohort (N=1,037) at 9 in-person assessments spanning ages 9 to 38 years. Leukocyte telomere length was measured at ages 26 and 38 years. Asthma was classified as life-course-persistent, childhood-onset not meeting criteria for persistence, and adolescent/adult onset. We tested associations between asthma and leukocyte telomere length using regression models. We tested for confounding of asthma-leukocyte telomere length associations using covariate adjustment. We tested serum C-reactive protein and white blood cell counts as potential mediators of asthma-leukocyte telomere length associations. Results. Study members with life-course-persistent asthma had shorter leukocyte telomere length as compared to sex- and age-matched peers with no reported asthma. In contrast, leukocyte telomere length in study members with childhood-onset and adolescent/adult-onset asthma was not different from leukocyte telomere length in peers with no reported asthma. Adjustment for life histories of obesity and smoking did not change results. Study members with life-course-persistent asthma had elevated blood eosinophil counts. Blood eosinophil count mediated 29% of the life-course-persistent asthma-leukocyte telomere length association. Conclusions. Life-course-persistent asthma is related to a proposed biomarker of accelerated aging, possibly via systemic eosinophilic inflammation. Life histories of asthma can inform studies of aging.
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Employment among schoolchildren and its associations with adult substance use, psychological wellbeing, and academic achievement | 2014
Iosua, E., Gray, A.R., McGee,
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Journal of Adolescent Health, 2014, 55(4), 542-548.
http://www.jahonline.org/article/S1054-139X(14)00184-0/abstract
Our ref: RO655
Purpose: To examine the association between paid part-time employment among schoolchildren, and adult substance use, psychological wellbeing, and academic achievement. Methods: Longitudinal data from the Dunedin Multidisciplinary Health and Development Study were used to evaluate the association between employment at each of 11, 13, and 15 years, and adult smoking, regular alcohol binge drinking, regular cannabis use, Sense of Coherence, social participation, positive coping style, prosociality, no formal qualifications, and university degree. Associations were initially assessed using unadjusted regression analyses and then adjusted for the potential childhood confounders IQ, reading development, Student’s Perception of Ability Scale, socioeconomic disadvantage, family climate, harsh parent-child interaction, parental opinion of their child’s attitude to school, and child’s personal attitude to school. Results: Employment at 11 years of age was associated with a lower odds of adult smoking; the odds of subsequent regular alcohol binge drinking were greater for those who were employed at age 13; and higher adult rates of social participation and prosociality were identified for adolescents who were employed at 15 years of age. When the potential confounders were con- trolled, employment at age 13 was predictive of both adult smoking and regular binge drinking, and working at 15 years of age was protective against regular cannabis use and associated with greater social participation. Conclusion: There is no consistent evidence that exposing schoolchildren to part-time employment compromised subsequent health, wellbeing, and education in a developed country.
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Childhood maltreatment, juvenile disorders and adult post-traumatic stress disorder: A prospective investigation | 2014
Breslau, N., Koenen, K., Swanson,
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Psychological Medicine, 2014, 44(9), 1937–1945.
Link to full publication »
Our ref: RO654
Background We examine prospectively the influence of two separate but potentially inter-related factors in the etiology of post-traumatic stress disorder (PTSD): childhood maltreatment as conferring a susceptibility to the PTSD response to adult trauma and juvenile disorders as precursors of adult PTSD. Method The Dunedin Multidisciplinary Health and Development Study (DMHDS) is a birth cohort (n = 1037) from the general population of New Zealand's South Island, with multiple assessments up to age 38 years. DSM-IV PTSD was assessed among participants exposed to trauma at ages 26–38. Complete data were available on 928 participants. Results Severe maltreatment in the first decade of life, experienced by 8.5% of the sample, was associated significantly with the risk of PTSD among those exposed to adult trauma [odds ratio (OR) 2.64, 95% confidence interval (CI) 1.16–6.01], compared to no maltreatment. Moderate maltreatment, experienced by 27.2%, was not associated significantly with that risk (OR 1.55, 95% CI 0.85–2.85). However, the two estimates did not differ significantly from one another. Juvenile disorders (ages 11–15), experienced by 35% of the sample, independent of childhood maltreatment, were associated significantly with the risk of PTSD response to adult trauma (OR 2.35, 95% CI 1.32–4.18). Conclusions Severe maltreatment is associated with risk of PTSD response to adult trauma, compared to no maltreatment, and juvenile disorders, independent of earlier maltreatment, are associated with that risk. The role of moderate maltreatment remains unresolved. Larger longitudinal studies are needed to assess the impact of moderate maltreatment, experienced by the majority of adult trauma victims with a history of maltreatment.
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HSV-2 incidence by sex over four age periods to age 38 in a birth cohort | 2014
Dickson, N., Righarts, A., van Roode,
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Sexually Transmitted Infections, 2014, 90(3), 143-145.
http://sti.bmj.com/content/90/3/243.full
Our ref: RO652
Objectives: To examine herpes simplex virus type 2 (HSV-2) incidence over four periods to age 38 in a birth cohort, and to compare risks for men and women, taking into account sexual behaviour. Methods: At ages 21, 26, 32 and 38, participants in the Dunedin Multidisciplinary Health and Development Study were invited to provide serum for HSV-2 serology, and information on sexual behaviour. HSV-2 incidence rates were calculated for four age periods, and comparisons made by sex and period, taking into account number of sexual partners. Results: By age 38, 17.3% of men and 26.8% of women had ever been seropositive for HSV-2. Incidence peaked for women from age 21 to 26 (19.1 per 1000 person-years) and men from age 26 to 32 (14.1 per 1000 person-years); it fell markedly for both from age 32 to 38 (5.1 and 6.8 per 1000 person-years for men and women, respectively). Overall risk was significantly higher for women: adjusted incidence rate ratio 1.9 (95% CI 1.4 to 2.7); the sex difference was most marked from age 21 to 26 (3.4, 95% CI 1.9 to 6.3). Conclusions: Our findings are consistent with a greater biological susceptibility to HSV-2 among women, and with the increasing risk to the early/mid-20s for women and late 20s/early 30s for men, being driven by an increasing pool of prevalent infection. The reduced risk in the mid-30s is consistent with declining infectivity of long-term prevalent infections.
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Re-examining periodontal effects of smoking in a birth cohort study with an enhanced analytical approach. Part 1: cross-sectional associations at each age | 2014
Zeng, J., Williams, S.M., Fletcher,
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Journal of Periodontology, 2014, .
DOI: 10.1902/jop.2014.130577
Link to full publication »
Our ref: RO651
Background: Smoking is a major risk factor for periodontal disease. Conventional oral epidemiology approaches have found strong, consistent associations between chronic smoking and periodontal attachment loss (AL) through ages 26, 32, and 38, but those statistical methods disregarded the data’s hierarchical structure. We re-examined the association using hierarchical modelling in order to (1) overcome the limitations of an earlier approach (trajectory analysis) to the data, and (2) determine the robustness of the earlier inferences. Method: Periodontal examinations were conducted at ages 26, 32 and 38 in the Dunedin Multidisciplinary Health and Development Study. The number of participants examined at those three ages were 913, 918 and 913, respectively. Generalized Linear Mixed Modelling with a quasi-binomial approach was used to examine associations between chronic smoking and periodontal attachment loss. Results: At ages 26, 32 and 38, smokers had 3.5%, 12.8% and 23.2% (respectively) greater AL than non-smokers. Regular cannabis use was associated with greater AL after age 32, but not at age 26. Males had more AL than females. Participants with high plaque scores had consistently greater AL; those who were of persistently low SES (socio-economic status) had higher AL at age 32 and 38, but not at age 26. The amount of AL in anteriors was less than in premolars and molars. Gingival bleeding was associated with higher AL at ages 26, 32 and 38. Conclusions: The smoking-periodontitis association is observable with hierarchical modelling, providing strong evidence that chronic smoking is a risk factor for periodontitis.
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Translating Personality Psychology to Help Personalize Preventive Medicine for Young-Adult Patients | 2014
Israel, S., Moffitt, T. E., Belsky,
... Show all »
Journal of Personality and Social Psychology, 2014, 106(3), 484-498.
https://www.apa.org/pubs/journals/releases/psp-a0035687.pdf
Our ref: RO650
The rising number of newly insured young adults brought on by health care reform will soon increase demands on primary care physicians. Physicians will face more young adult patients, which presents an opportunity for more prevention-oriented care. In the present study, we evaluated whether brief observer reports of young adults’ personality traits could predict which individuals would be at greater risk for poor health as they entered midlife. Following the cohort of 1,000 individuals from the Dunedin Multidisciplinary Health and Development Study (Moffitt, Caspi, Rutter, & Silva, 2001), we show that very brief measures of young adults’ personalities predicted their midlife physical health across multiple domains (metabolic abnormalities, cardiorespiratory fitness, pulmonary function, periodontal disease, and systemic inflammation). Individuals scoring low on the traits of Conscientiousness and Openness to Experience went on to develop poorer health even after accounting for preexisting differences in education, socioeconomic status, smoking, obesity, self-reported health, medical conditions, and family medical history. Moreover, personality ratings from peer informants who knew participants well, and from a nurse and receptionist who had just met participants for the first time, predicted health decline from young adulthood to midlife despite striking differences in level of acquaintance. Personality effect sizes were on par with other well-established health risk factors such as socioeconomic status, smoking, and self-reported health. We discuss the potential utility of personality measurement to function as an inexpensive and accessible tool for health care professionals to personalize preventive medicine. Adding personality information to existing health care electronic infrastructures could also advance personality theory by generating opportunities to examine how personality processes influence doctor–patient communication, health service use, and patient outcomes.
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Smoking Cessation and Subsequent Weight Change | 2014
Robertson, L.A., McGee, R., Hancox,
... Show all »
Nicotine & Tobacco Research, 2014, 16(6), 867-871.
http://ntr.oxfordjournals.org/content/16/6/867.full.pdf+html
Our ref: RO649
Introduction: People who quit smoking tend to gain more weight over time than those who continue to smoke. Previous research using clinical samples of smokers suggests that quitters typically experience a weight gain of approximately 5kg in the year following smoking cessation, but these studies may overestimate the extent of weight gain in the general population. The existing population-based research in this area has some methodological limitations. Methods: We assessed a cohort of individuals born in Dunedin, New Zealand, in 1972–1973, at regular intervals from age 15 to 38. We used multiple linear regression analysis to investigate the association between smoking cessation between 21 and 38 years and subsequent change in body mass index (BMI) and weight, controlling for baseline BMI, socioeconomic status, physical activity, alcohol use, and parity (women). Results: Smoking status and outcome data were available at baseline and follow-up for N = 914 Study members. People who smoked at age 21 and who had quit by age 38 had a BMI on average 1.5kg/m2 greater than those who continued to smoke at age 38. This equated to a weight gain of approximately 5.7kg in men and 5.1kg in women above that of continuing smokers. However, the weight gain between age 21 and 38 among quitters was not significantly different to that of never-smokers. Conclusions: The amount of long-term weight gained after quitting smoking is likely to be lower than previous estimates based on research with clinical samples. On average, quitters do not experience greater weight gain than never-smokers.
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Internalizing disorders and leukocyte telomere erosion: a prospective study of depression, generalized anxiety disorder and post-traumatic stress disorder | 2014
Shalev, I., Moffitt, T.E., Braithwaite,
... Show all »
Molecular Psychiatry, 2014, 19(11), 1163-1170.
10.1038/mp.2013.183
Link to full publication »
Our ref: RO648
There is evidence that persistent psychiatric disorders lead to age-related disease and premature mortality. Telomere length has emerged as a promising biomarker in studies that test the hypothesis that internalizing psychiatric disorders are associated with accumulating cellular damage. We tested the association between the persistence of internalizing disorders (depression, generalized anxiety disorder and post-traumatic stress disorder) and leukocyte telomere length (LTL) in the prospective longitudinal Dunedin Study (n = 1037). Analyses showed that the persistence of internalizing disorders across repeated assessments from ages 11 to 38 years predicted shorter LTL at age 38 years in a doseresponse manner, specifically in men (' = - 0.137, 95% confidence interval (CI): -0.232, -0.042, P = 0.005). This association was not accounted for by alternative explanatory factors, including childhood maltreatment, tobacco smoking, substance dependence, psychiatric medication use, poor physical health or low socioeconomic status. Additional analyses using DNA from blood collected at two time points (ages 26 and 38 years) showed that LTL erosion was accelerated among men who were diagnosed with internalizing disorder in the interim (' = - 0.111, 95% CI: -0.184, -0.037, P = 0.003). No significant associations were found among women in any analysis, highlighting potential sex differences in internalizing-related telomere biology. These findings point to a potential mechanism linking internalizing disorders to accelerated biological aging in the first half of the life course, particularly in men. Because internalizing disorders are treatable, the findings suggest the hypothesis that treating psychiatric disorders in the first half of the life course may reduce the population burden of age-related disease and extend health expectancy.
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Suicide attempt in young people: A signal for long-term healthcare and social needs | 2014
Goldman-Mellor, S., Caspi, A., Harrington,
... Show all »
JAMA Psychiatry, 2014, 71(2), 119-127.
10.1001/jamapsychiatry.2013.2803
Link to full publication »
Our ref: RO647
Importance Suicidal behavior has increased since the onset of the global recession, a trend that may have long-term health and social implications. Objective To test whether suicide attempts among young people signal increased risk for later poor health and social functioning above and beyond a preexisting psychiatric disorder. Design We followed up a cohort of young people and assessed multiple aspects of their health and social functioning as they approached midlife. Outcomes among individuals who had self-reported a suicide attempt up through age 24 years (young suicide attempters) were compared with those who reported no attempt through age 24 years (nonattempters). Psychiatric history and social class were controlled for. Setting and Participants The population-representative Dunedin Multidisciplinary Health and Development Study, which involved 1037 birth cohort members comprising 91 young suicide attempters and 946 nonattempters, 95% of whom were followed up to age 38 years. Main Outcomes and Measures Outcomes were selected to represent significant individual and societal costs: mental health, physical health, harm toward others, and need for support. Results As adults approaching midlife, young suicide attempters were significantly more likely to have persistent mental health problems (eg, depression, substance dependence, and additional suicide attempts) compared with nonattempters. They were also more likely to have physical health problems (eg, metabolic syndrome and elevated inflammation). They engaged in more violence (eg, violent crime and intimate partner abuse) and needed more social support (eg, long-term welfare receipt and unemployment). Furthermore, they reported being lonelier and less satisfied with their lives. These associations remained after adjustment for youth psychiatric diagnoses and social class. Conclusions and Relevance Many young suicide attempters remain vulnerable to costly health and social problems into midlife. As rates of suicidal behavior rise with the continuing global recession, additional suicide prevention efforts and long-term monitoring and after-care services are needed.
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Lifelong Impact of Early Self-Control | 2013
Terrie E. Moffitt, Richie Poulton, and Avshalom Caspi
American Scientist, 2013, 101 352-359.
Link to full publication »
Our ref: PJ39
The Dunedin Study is a longitudinal research effort that has followed more than 1,000 people from birth over four decades, collecting information on their physical health and social wellbeing. Over the past 38 years, the participants have been physically and psychologically examined 12 times, at birth and then at ages 3, 5, 7,9,11,13,15,18,21,26,32, and 38.
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Tobacco Smoking in Adolescence Predicts Maladaptive Coping Styles in Adulthood | 2013
McGee, Rob, Williams, Sheila, Nada-Raja,
... Show all »
Nicotine & Tobacco Research, 2013, 15(12), 1971-1977.
10.1093/ntr/ntt081
Link to full publication »
Our ref: RO649.2
Introduction: To examine the extent to which cigarette smoking in adolescence is associated with maladaptive versus adaptive coping behaviors in adulthood.Method: The data came from a longitudinal study of New Zealand adolescents followed into adulthood at age 32 years. Using structural equation modeling (SEM), we examined the predictive association between daily smoking of cigarettes and symptoms of tobacco dependence from 18 to 26 years of age and later coping at age 32 years. We included pathways from childhood family disadvantage in addition to both adolescent stress-worry and adult coping in the model.Results: SEM revealed that cigarette smoking had a small but direct inverse effect on later adaptive coping (-.14) and a direct effect on maladaptive coping (.23) independent of the relationships between adolescent coping and stress-worry and later adult coping.Conclusions: The findings are consistent with the hypothesis that tobacco smoking may inhibit the development of self-efficacy or one’s ability to act with appropriate coping behaviors in any given situation.
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Secular changes in the associations between risk factors and BMI at ages 3 and 7 in two Dunedin cohorts | 2013
Williams, S.M., Taylor, R.W., Taylor,
... Show all »
Pediatric Obesity, 2013, 8(1), 21-30.
http://onlinelibrary.wiley.com/doi/10.1111/j.2047-6310.2012.00081.x/pdf
Our ref: RO634.2
Objective: Using two cohorts born 29 years apart in Dunedin, New Zealand we aim to examine changes in risk factors and their associations with body mass index (BMI) at ages 3 and 7 years, and estimate their contribution to the secular changes in BMI at age 7 years. Methods: Birth weight and anthropometric measures at ages 3, 5 and 7 years were obtained for 974 participants in the Dunedin Multidisciplinary Health and Development Study (DMHDS), born in 1972–1973, and 241 in the Family Lifestyle, Activity, Movement and Eating Study (FLAME), born in 2001–2002. Information about maternal age, education and smoking in pregnancy, as well as breastfeeding, children's television time and time in bed, was obtained by questionnaire. Results: The increase in BMI over the 29-year period was 0.84 (95% CI 0.61, 1.06) kg m-2 at age 7. A 1-unit difference in the mother's BMI was associated with a 0.06 (0.03, 0.08) kg m-2 difference in offspring in both studies; the 3.4 (2.8, 4.0) kg m-2 increase in the mothers’ BMIs accounts for a change of 0.19 kg m-2 in the children's BMI. The much smaller generational increase in fathers’ BMI (0.7 kg m-2) correspondingly had a more limited effect on change in child BMI over time (0.06 kg m-2). Although smoking in pregnancy decreased by 15% (8, 21) its association with BMI increased from 0.20 (-0.01, 0.42) in the DMHDS cohort to 1.24 (0.76, 1.71) kg m-2 in the FLAME cohort, contributing 0.18 kg m-2 to the increase in children's BMI. Conclusions: Societal factors such as higher maternal BMI and smoking in pregnancy contribute most to the secular increase in BMI, with changes in behavioural factors, including sleep and television viewing, having little effect in this setting.
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Permanent dentition caries through the first half of life | 2013
Broadbent, J. M. , Foster-Page, L.A., Thomson,
... Show all »
British Dental Journal, 2013, 215(215), E12.
http://www.nature.com/bdj/journal/v215/n7/full/sj.bdj.2013.991.html
Our ref: RO646
Aim: To describe the occurrence of dental caries at the person, tooth and tooth surface level from childhood to early mid-life. Background: No studies have reported on age and caries experience in a population-based sample through the first half of life. Methods: Prospective cohort study of a complete birth cohort (n = 1,037) born in 1972/73 in Dunedin, New Zealand. Dental examinations were conducted at ages 5, 9, 15, 18, 26, 32 and 38, and participation rates remained high. Surface-level caries data were collected at each age (WHO basic methods). Statistical analyses and graphing of data were undertaken using Intercooled Stata Version 10. Results: Data are presented on dental caries experience in the permanent dentition at ages 9, 15, 18, 26, 32 and 38. Percentile curves are charted and reported for person-level caries experience. Data are also presented on the number of decayed teeth and tooth surfaces, (including root surfaces at age 38), as a function of the number of teeth and surfaces present, respectively. Across the cohort, the number of tooth surfaces affected by dental caries increased by approximately 0.8 surfaces per year (on average), while the percentage of at-risk tooth surfaces affected by caries increased by approximately 0.5% per year, with negligible variation in that rate throughout the observation period. Conclusion: These unique data show clearly that dental caries continues as a disease of adulthood, remaining important beyond childhood and adolescence and that rates of dental caries over time remain relatively constant.
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Is Obesity Associated With a Decline in Intelligence Quotient During the First Half of the Life Course? | 2013
Belsky, D.W., Caspi, A., Goldman-Mellor,
... Show all »
American Journal of Epidemiology, 2013, First published online 12 September 2013, doi: 10.1093/aje/kwt135.
10.1093/aje/kwt135
Link to full publication »
Our ref: RO645
Cross-sectional studies have found that obesity is associated with low intellectual ability and neuroimaging abnormalities in adolescence and adulthood. Some have interpreted these associations to suggest that obesity causes intellectual decline in the first half of the life course. We analyzed data from a prospective longitudinal study to test whether becoming obese was associated with intellectual decline from childhood to midlife. We used data from the ongoing Dunedin Multidisciplinary Health and Development Study, a population-representative birth cohort study of 1,037 children in New Zealand who were followed prospectively from birth (1972'1973) through their fourth decade of life with a 95% retention rate. Intelligence quotient (IQ) was measured in childhood and adulthood. Anthropometric measurements were taken at birth and at 12 subsequent in-person assessments. As expected, cohort members who became obese had lower adulthood IQ scores. However, obese cohort members exhibited no excess decline in IQ. Instead, these cohort members had lower IQ scores since childhood. This pattern remained consistent when we accounted for children's birth weights and growth during the first years of life, as well as for childhood-onset obesity. Lower IQ scores among children who later developed obesity were present as early as 3 years of age. We observed no evidence that obesity contributed to a decline in IQ, even among obese individuals who displayed evidence of the metabolic syndrome and/or elevated systemic inflammation.
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Microvascular Abnormality in Schizophrenia as Shown by Retinal Imaging | 2013
Meier, M.H., Shalev, I., Moffitt,
... Show all »
American Journal of Psychiatry, 2013, 170(170), 1451-1459.
Link to full publication »
Our ref: RO644
Objective Retinal and cerebral microvessels are structurally and functionally homologous, but unlike cerebral microvessels, retinal microvessels can be noninvasively measured in vivo by retinal imaging. The authors tested the hypothesis that individuals with schizophrenia exhibit microvascular abnormality and evaluated the utility of retinal imaging as a tool for schizophrenia research. Method Participants were members of the Dunedin Study, a population-representative cohort followed from birth with 95% retention. Study members underwent retinal imaging at age 38. The authors assessed retinal arteriolar and venular caliber for all members of the cohort, including individuals who developed schizophrenia. Results Study members who developed schizophrenia were distinguished by wider retinal venules, suggesting microvascular abnormality reflective of insufficient brain oxygen supply. Analyses that controlled for confounding health conditions suggested that wider retinal venules are not simply an artifact of co-occurring health problems in schizophrenia patients. Wider venules were also associated with a dimensional measure of adult psychosis symptoms and with psychosis symptoms reported in childhood. Conclusions The findings provide initial support for the hypothesis that individuals with schizophrenia show microvascular abnormality. Moreover, the results suggest that the same vascular mechanisms underlie subthreshold symptoms and clinical disorder and that these associations may begin early in life. These findings highlight the promise of retinal imaging as a tool for understanding the pathogenesis of schizophrenia.
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Neuropsychological Decline in Schizophrenia from the Premorbid to Post-Onset Period: Evidence from a Population-Representative Longitudinal Study | 2013
Meier, M.H., Caspi, A., Reichenberg,
... Show all »
American Journal of Psychiatry, 2013, AJP in advance September 2013, doi:10.1176/appi.ajp.2013.12111438.
10.1093/aje/kwt135
Link to full publication »
Our ref: RO643
Objective Despite the widespread belief that neuropsychological decline is a cardinal feature of the progression from the premorbid stage to the chronic form of schizophrenia, few longitudinal studies have examined change in neuropsychological functioning from before to after illness onset. The authors examined whether neuropsychological decline is unique to schizophrenia, whether it is generalized or confined to particular mental functions, and whether individuals with schizophrenia also have cognitive problems in everyday life. Method Participants were members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972 and 1973 and followed prospectively to age 38, with 95% retention. Assessment of IQ and specific neuropsychological functions was conducted at ages 7, 9, 11, and 13, and again at age 38. Informants also reported on any cognitive problems at age 38. Results Individuals with schizophrenia exhibited declines in IQ and in a range of mental functions, particularly those tapping processing speed, learning, executive function, and motor function. There was little evidence of decline in verbal abilities or delayed memory, however, and the developmental progression of deficits in schizophrenia differed across mental functions. Processing speed deficits increased gradually from childhood to beyond the early teen years, whereas verbal deficits emerged early but remained static thereafter. Neuropsychological decline was specific to schizophrenia, as no evidence of decline was apparent among individuals with persistent depression, children with mild cognitive impairment, individuals matched on childhood risk factors for schizophrenia, and psychiatrically healthy individuals. Informants also noticed more cognitive problems in individuals with schizophrenia. Conclusions There is substantial neuropsychological decline in schizophrenia from the premorbid to the postonset period, but the extent and developmental progression of decline varies across mental functions. Findings suggest that different pathophysiological mechanisms may underlie deficits in different mental functions.
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Diagnostic transitions from childhood to adolescence to early adulthood | 2013
Copeland, W.E., Adair, C.E., Smetanin,
... Show all »
Journal of Child Psychology and Psychiatry, 2013, 54(54), 791-799.
Link to full publication »
Our ref: RO642
Background: Quantifying diagnostic transitions across development is needed to estimate the long-term burden of mental illness. This study estimated patterns of diagnostic transitions from childhood to adolescence and from adolescence to early adulthood. Methods: Patterns of diagnostic transitions were estimated using data from three prospective, longitudinal studies involving close to 20,000 observations of 3,722 participants followed across multiple developmental periods covering ages 9'30. Common DSM psychiatric disorders were assessed in childhood (ages 9'12; two samples), adolescence (ages 13'18; three samples), and early adulthood (ages 19 to age 32; three samples) with structured psychiatric interviews and questionnaires. Results: Having a disorder at an early period was associated with at least a threefold increase in odds for having a disorder at a later period. Homotypic and heterotypic transitions were observed for every disorder category. The strongest evidence of continuity was seen for behavioral disorders (particularly ADHD) with less evidence for emotional disorders such as depression and anxiety. Limited evidence was found in adjusted models for behavioral disorders predicting later emotional disorders. Adult substance disorders were preceded by behavioral disorders, but not anxiety or depression. Conclusions: Having a disorder in childhood or adolescence is a potent risk factor for a range of psychiatric problems later in development. These findings provide further support for prevention and early life intervention efforts and suggest that treatment at younger ages, while justified in its own right, may also have potential to reduce the risk for disorders later in development.
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The p Factor: One general psychopathology factor in the structure of psychiatric disorders? | 2013
Caspi, A., Houts, R., Belsky,
... Show all »
Clinical Psychological Science, 2013, DOI: 10.1177/2167702613497473 .
Link to full publication »
Our ref: RO641
Mental disorders traditionally have been viewed as distinct, episodic, and categorical conditions. This view has been challenged by evidence that many disorders are sequentially comorbid, recurrent/chronic, and exist on a continuum. Using the Dunedin Multidisciplinary Health and Development Study, we examined the structure of psychopathology, taking into account dimensionality, persistence, co-occurrence, and sequential comorbidity of mental disorders across 20 years, from adolescence to midlife. Psychiatric disorders were initially explained by three higher-order factors (Internalizing, Externalizing, and Thought Disorder) but explained even better with one General Psychopathology dimension. We have called this dimension the p factor because it conceptually parallels a familiar dimension in psychological science: the g factor of general intelligence. Higher p scores are associated with more life impairment, greater familiality, worse developmental histories, and more compromised early-life brain function. The p factor explains why it is challenging to find causes, consequences, biomarkers, and treatments with specificity to individual mental disorders. Transdiagnostic approaches may improve research.
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The natural history of periodontal attachment loss during the third and fourth decades of life: findings from the Dunedin Study | 2013
Thomson, W. M. , Shearer, D.M., Broadbent,
... Show all »
Journal of Clinical Periodontology, 2013, 40(40), 672-680.
doi/10.1111/jcpe.12108/pdf
Link to full publication »
Our ref: RO640
Aim: To describe changes in the occurrence of periodontal attachment loss through ages 26, 32 and 38 in a complete birth cohort. Materials and methods: Systematic periodontal examinations conducted at ages 26, 32 and 38 in a longstanding New Zealand cohort study (N = 1037). Periodontitis extent data were used to assign participants to periodontitis trajectories using group-based trajectory analysis. Results: 831 individuals were periodontally examined at all three ages; the prevalence and extent of attachment loss increased as the cohort aged. Between 26 and 32, one in nine participants had 1+ sites showing new or progressing attachment loss); that proportion almost doubled between ages 32 and 38. Four periodontitis trajectory groups were identified, comprising 54.2%, 31.7%, 11.0% and 3.1% of the cohort; these were termed the 'no disease', 'minor disease', 'moderate disease' and 'extensive disease' trajectory groups, respectively. Those who had smoked tobacco at all ages from 15 through 38 were at higher risk of being in the 'moderate disease' or 'extensive disease' trajectory groups. There was a similar risk gradient for those who were in the highest 20% of cannabis usage. Conclusions: Periodontitis commences relatively early in adulthood, and its progression accelerates with age, particularly among smokers.
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Polygenic risk and the development and course of asthma: an analysis of data from a four-decade longitudinal study | 2013
Belsky, D.W., Sears, M.R., Hancox,
... Show all »
Lancet Respiratory Medicine, 2013, 1(1), 453-461.
http://www.thelancet.com/journals/lanres/article/PIIS2213-2600(13)70101-2/abstract
Our ref: RO639
Background Genome-wide association studies (GWAS) have discovered loci that predispose individuals to asthma. To integrate these new discoveries with emerging models of asthma pathobiology, we aimed to test how genetic discoveries relate to developmental and biological characteristics of asthma. Methods In this prospective longitudinal study, we investigated a multilocus profile of genetic risk derived from published GWAS of asthma case status. We then tested associations between this genetic risk score and developmental and biological characteristics of asthma in participants enrolled in a population-based long-running birth cohort, the Dunedin Multidisciplinary Health and Development Study (n=1037). We used data on asthma onset, asthma persistence, atopy, airway hyper-responsiveness, incompletely reversible airflow obstruction, and asthma-related school and work absenteeism and hospital admissions obtained during nine prospective assessments spanning the ages of 9 to 38 years. Analyses included cohort members of European descent from whom genetic data had been obtained. Findings Of the 880 cohort members included in our analysis, those at higher genetic risk developed asthma earlier in life than did those with lower genetic risk (hazard ratio [HR] 1·12, 95% CI 1·011·26). Of cohort members with childhood-onset asthma, those with higher genetic risk were more likely to develop life-course-persistent asthma than were those with a lower genetic risk (relative risk [RR] 1·36, 95% CI 1·141·63). Participants with asthma at higher genetic risk more often had atopy (RR 1·07, 1·011·14), airway hyper-responsiveness (RR 1·16, 1·031·32), and incompletely reversible airflow obstruction (RR 1·28, 1·041·57) than did those with a lower genetic risk. They were also more likely to miss school or work (incident rate ratio 1·38, 1·021·86) and be admitted to hospital (HR 1·38, 1·071·79) because of asthma. Genotypic information about asthma risk was independent of and additive to information derived from cohort members' family histories of asthma. Interpretation Our findings confirm that GWAS discoveries for asthma are associated with a childhood-onset phenotype. Genetic risk assessments might be able to predict which childhood-onset asthma cases remit and which become life-course-persistent, who might develop impaired lung function, and the burden of asthma in terms if missed school and work and hospital admissions, although these predictions are not sufficiently sensitive or specific to support immediate clinical translation.
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Prospective developmental subtypes of alcohol dependence from age 18 to 32 years: Implications for nosology, etiology, and intervention | 2013
Meier, M.H., Caspi, A., Houts,
... Show all »
Development and Psychopathology, 2013, 25(25), 785-800.
10.1017/S0954579413000175
Link to full publication »
Our ref: RO638
The purpose of the present study was to identify child and adult correlates that differentiate (a) individuals with persistent alcohol dependence from individuals with developmentally-limited alcohol dependence and (b) individuals with adult-onset alcohol dependence from individuals who never diagnose. Participants are 1,037 members of the Dunedin longitudinal study, a birth cohort followed prospectively from birth until age 32. Past-year DSM-IV alcohol dependence diagnoses were ascertained with structured diagnostic interviews at ages 18, 21, 26, and 32. Individuals were classified as developmentally-limited, persistent, or adult-onset subtypes based on their time-ordered pattern of diagnoses. The persistent subtype generally exhibited the worst scores on all correlates, including family psychiatric history, adolescent and adult externalizing and internalizing problems, adolescent and adult substance use, adult quality of life, and coping strategies. The prospective predictors that distinguished them from the developmentally-limited subtype involved family liability, adolescent negative affectivity, daily alcohol use, and frequent marijuana use. Furthermore, young people who developed the persistent subtype of alcohol dependence were distinguished from the developmentally-limited subtype by an inability to reduce drinking and by continued use despite problems, already by age 18. The adult-onset group members were virtually indistinguishable from ordinary cohort members as children or adolescents, but, in adulthood, adult-onset cases were distinguished by problems with depression, substance use, stress, and strategies for coping with stress. Information about age-of-onset and developmental course is fundamental for identifying subtypes of alcohol dependence. Subtype-specific etiologies point to targeted prevention and intervention efforts based on characteristics of each subtype.
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Retinal vessel caliber and lifelong neuropsychological functioning: Retinal imaging as an investigative tool for cognitive epidemiology | 2013
Shalev, I., Moffitt, T.E., Wong,
... Show all »
Psychological Science, 2013, 24(24), 1198-1207.
Link to full publication »
Our ref: RO637
Why do more intelligent people live healthier and longer lives? One possibility is that intelligence tests assess health of the brain, but psychological science has lacked technology to evaluate this hypothesis. Digital retinal imaging, a new, noninvasive method to visualize microcirculation in the eye, may reflect vascular conditions in the brain. We studied the association between retinal vessel caliber and neuropsychological functioning in the representative Dunedin birth cohort. Wider venular caliber was associated with poorer neuropsychological functioning at midlife, independently of potentially confounding factors. This association was not limited to any specific test domain and extended to informants' reports of cohort members' cognitive difficulties in everyday life. Moreover, wider venular caliber was associated with lower childhood IQ tested 25 years earlier. The findings indicate that retinal venular caliber may be an indicator of neuropsychological health years before the onset of dementing diseases and suggest that digital retinal imaging may be a useful investigative tool for psychological science.
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Polygenic risk and the developmental progression to heavy, persistent smoking and nicotine dependence: Evidence from a 4-Decade Longitudinal Study | 2013
Belsky, D.W., Moffitt, T.E., Poulton,
... Show all »
JAMA Psychiatry, 2013, 70(70), 534-542.
http://archpsyc.jamanetwork.com/article.aspx?articleid=1672838
Our ref: RO636
Importance: Genome-wide hypothesis-free discovery methods have identified loci that are associated with heavy smoking in adulthood. Research is needed to understand developmental processes that link newly discovered genetic risks with adult heavy smoking. Objective: To test how genetic risks discovered in genome-wide association studies of adult smoking influence the developmental progression of smoking behavior from initiation through conversion to daily smoking, progression to heavy smoking, nicotine dependence, and struggles with cessation. Design: A 38-year, prospective, longitudinal study of a representative birth cohort. Setting: The Dunedin Multidisciplinary Health and Development Study of New Zealand. Participants: The study included 1037 male and female participants. Exposure: We assessed genetic risk with a multilocus genetic risk score. The genetic risk score was composed of single-nucleotide polymorphisms identified in 3 meta-analyses of genome-wide association studies of smoking quantity phenotypes. Main Outcomes and Measures: Smoking initiation, conversion to daily smoking, progression to heavy smoking, nicotine dependence (Fagerstr'm Test of Nicotine Dependence), and cessation difficulties were evaluated at 8 assessments spanning the ages of 11 to 38 years. Results: Genetic risk score was unrelated to smoking initiation. However, individuals at higher genetic risk were more likely to convert to daily smoking as teenagers, progressed more rapidly from smoking initiation to heavy smoking, persisted longer in smoking heavily, developed nicotine dependence more frequently, were more reliant on smoking to cope with stress, and were more likely to fail in their cessation attempts. Further analysis revealed that 2 adolescent developmental phenotypes'early conversion to daily smoking and rapid progression to heavy smoking'mediated associations between the genetic risk score and mature phenotypes of persistent heavy smoking, nicotine dependence, and cessation failure. The genetic risk score predicted smoking risk over and above family history. Conclusions and Relevance: Initiatives that disrupt the developmental progression of smoking behavior among adolescents may mitigate genetic risks for developing adult smoking problems. Future genetic research may maximize discovery potential by focusing on smoking behavior soon after smoking initiation and by studying young smokers.
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Stability and change in same-sex attraction, experience, and identity by sex and age in a New Zealand Birth Cohort | 2013
Dickson, N., van Roode, T., Cameron,
... Show all »
Archives of Sexual Behaviour, 2013, 42(42), 753-763.
http://link.springer.com/article/10.1007/s10508-012-0063-z
Our ref: RO635
Gaps remain in knowledge of changes in sexual orientation past adolescence and early adulthood. A longitudinal study of a New Zealand birth cohort was used to examine differences by age and sex in change in sexual attraction between 21 (1993/1994) and 38 years (2010/2011), sexual experiences between 26 and 38 years, and sexual identity between 32 and 38 years. Any same-sex attraction was significantly more common among women than men at all ages. Among women, any same-sex attraction increased up to age 26 (from 8.8 to 16.6 %), then decreased slightly by age 38 (12.0 %); among men, prevalence was significantly higher at age 38 (6.5 %) than 21 (4.2 %), but not in the intermediate assessments. It is likely that the social environment becoming more tolerant was responsible for some of the changes. Same-sex attraction was much more common than same-sex experiences or a same-sex identity, especially among women, with no major sex differences in these latter dimensions. Women exhibited much greater change in sexual attraction between assessments than men; for change in experiences and identity, sex differences were less marked and not statistically confirmed. Changes in the respective dimensions appeared more likely among those initially with mixed attraction and experiences, and among those initially identifying as bisexual, but this did not account for the sex difference in likelihood of change. These results provide contemporary information about the extent and variation of reported sexual attraction, experiences, and identity that we show continues across early and mid-adulthood.
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Forceps birth delivery, allergic sensitisation and asthma: a population-based cohort study | 2013
Hancox, R. J. , Landhuis, C.E., Sears,
... Show all »
Clinical and Experimental Allergy, 2013, 43(43), 332-336.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2222.2012.04058.x/full
Our ref: RO634
Background: Studies indicate an increased risk of allergies among children born by caesarean section, possibly because immune development is altered by avoiding exposure to maternal vaginal flora. It is unknown if other obstetric interventions are associated with allergies. Objective: To assess associations between delivery with forceps assistance and development of atopy and asthma. Methods: In a population-based cohort of 1037 individuals born in 1972/73, atopy was assessed by skin-prick tests for common allergens at ages 13 and 32 years. A history of asthma was obtained at the same ages. Associations between birth with forceps assistance, atopy, and asthma were assessed with adjustments for sex, head circumference at birth, parental atopy disease, birth order, and socioeconomic status. Results: Children born using forceps were more likely to have atopy at ages 13 (53% vs. 44%) and 32 (68% vs 59%). They were also more likely to have asthma (21% vs. 11% and 23% vs. 16% at ages 13 and 32 respectively). Except for asthma at age 13, these associations were not statistically significant after adjustment for multiple confounding factors. Conclusions & Clinical Relevance: Delivery with forceps assistance is associated with an increased risk of atopy and asthma, but the associations were weaker after adjustment for confounding factors. The previously reported association between caesarean birth and atopic disease may be due to confounding rather than altered exposure to maternal flora, although other factors associated with a difficult labour cannot be ruled out.
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Childhood and adolescent television viewing and antisocial behavior in early adulthood | 2013
Robertson, L.A., McAnally, H.M., Hancox,
... Show all »
Pediatrics, 2013, 131(131), 439-446.
10.1542/peds.2012-1582
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Our ref: RO633
OBJECTIVE: To investigate whether excessive television viewing throughout childhood and adolescence is associated with increased antisocial behavior in early adulthood. METHODS: We assessed a birth cohort of 1037 individuals born in Dunedin, New Zealand, in 1972'1773, at regular intervals from birth to age 26 years. We used regression analysis to investigate the associations between television viewing hours from ages 5 to 15 years and criminal convictions, violent convictions, diagnosis of antisocial personality disorder, and aggressive personality traits in early adulthood. RESULTS: Young adults who had spent more time watching television during childhood and adolescence were significantly more likely to have a criminal conviction, a diagnosis of antisocial personality disorder, and more aggressive personality traits compared with those who viewed less television. The associations were statistically significant after controlling for sex IQ, socioeconomic status, previous antisocial behavior, and parental control. The associations were similar for both sexes, indicating that the relationship between television viewing and antisocial behavior is similar for male and female viewers. CONCLUSIONS: Excessive television viewing in childhood and adolescence is associated with increased antisocial behavior in early adulthood. The findings are consistent with a causal association and support the American Academy of Pediatrics recommendation that children should watch no more than 1 to 2 hours of television each day.
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