Search

Over the last 50 years Dunedin Study researchers have published more than 1400 peer-reviewed journal articles, books, and reports on many aspects of human health and development. In this 50th anniversary piece we reflect on (i) our historical roots and necessary re-invention through time; (ii) the underpinning principles that have contributed to our success; (iii) some selected examples of high-impact work from the behavioural, oral health, and respiratory domains; (iv) some of the challenges we have encountered over time and how to overcome these; and (vi) review where we see the Study going in the future. We aim to present some of the 'back story', which is typically undocumented and oft lost to memory, and thus focus on 'know-how'. Our hope is to humanise our research, share insights, and to acknowledge the real heroes of the Study – the 1037 Study members, their families and their friends, who have collectively given so much, for so long, in the hope of helping others. [ABSTRACT FROM AUTHOR]

Adverse childhood experiences (ACEs) are associated with poorer health, which has spurred public health efforts to reduce the number of adverse events children experience. Unfortunately, it is unlikely that all ACEs can be prevented. For adults who already experienced ACEs in childhood, what psychological, social, and behavioral intervention targets might reduce risk for negative health outcomes? To provide insight into the "black box" of psychosocial mechanisms linking ACEs to poor health, our study used data from the Dunedin Study, a longitudinal cohort assessed from birth to age 45. Mediation models (N = 859) were used to examine whether candidate psychosocial variables in adulthood explained the association between childhood ACEs and health in midlife. Potential psychosocial mediators included stressful life events, perceived stress, negative emotionality, and health behaviors. Children who experienced more ACEs had poorer health in midlife. They also had significantly more stressful life events, more perceived stress, more negative emotionality, and unhealthier behaviors as adults. These mediators were each independently associated with poorer health in midlife and statistically mediated the association between ACEs and midlife health. Health behaviors evidenced the strongest indirect effect from ACEs to midlife health. Together, these psychosocial mediators accounted for the association between ACEs in childhood and health three decades later. Public health efforts to mitigate the health consequences of ACEs could aim to reduce the stressful life events people experience, reduce negative emotionality, reduce perceived stress, or improve health behaviors among adults who experienced childhood adversity. [ABSTRACT FROM AUTHOR]

Objective: Bullying is the act of intentionally and repeatedly causing harm to someone who has difficulty defending him- or herself, and is a relatively widespread school-age phenomenon. Being the victim of bullying is associated with a broad spectrum of emotional problems; however, not all children who are bullied go on to develop such problems. Method: We tested the hypothesis that the relationship between bullying victimization and emotional problems was moderated by variation in the serotonin transporter ("5-HTT") gene in 2,232 British children comprising the Environmental Risk (E-Risk) study cohort. Results: Our data supported the hypothesis that children's bullying victimization leads to their developing emotional problems, and that genetic variation in the "5-HTT"LPR moderates this relationship. Specifically, frequently bullied children with the SS genotype were at greater risk for developing emotional problems at age 12 than were children with the SL or LL genotype. Furthermore, we demonstrated that this genetic moderation persisted (a) after controlling for children's previctimization emotional problems by assessing intraindividual change in problems between ages 5 and 12 years, and (b) after controlling for other risk factors shared by children growing up in the same family by comparing emotional problems in twins discordant for bullying victimization. Conclusions: These findings are further evidence that the "5-HTT"LPR moderates the risk of emotional disturbance after exposure to stressful events. (Contains 3 figures and 1 table.)

Objective: To evaluate whether including children with onset of symptoms between ages 7 and 12 years in the ADHD diagnostic category would: (a) increase the prevalence of the disorder at age 12, and (b) change the clinical and cognitive features, impairment profile, and risk factors for ADHD compared with findings in the literature based on the DSM-IV definition of the disorder. Method: A birth cohort of 2,232 British children was prospectively evaluated at ages 7 and 12 years for ADHD using information from mothers and teachers. The prevalence of diagnosed ADHD at age 12 was evaluated with and without the inclusion of individuals who met DSM-IV age-of-onset criterion through mothers' or teachers' reports of symptoms at age 7. Children with onset of ADHD symptoms before versus after age 7 were compared on their clinical and cognitive features, impairment profile, and risk factors for ADHD. Results: Extending the age-of-onset criterion to age 12 resulted in a negligible increase in ADHD prevalence by age 12 years of 0.1%. Children who first manifested ADHD symptoms between ages 7 and 12 did not present correlates or risk factors that were significantly different from children who manifested symptoms before age 7. Conclusions: Results from this prospective birth cohort might suggest that adults who are able to report symptom onset by age 12 also had symptoms by age 7, even if they are not able to report them. The data suggest that the prevalence estimate, correlates and risk factors of ADHD will not be affected if the new diagnostic scheme extends the age-of-onset criterion to age 12. (Contains 1 table.)

Researchers have hypothesized that over the life course, criminal offending varies with problems in other domains, including life failure and physical and mental health. To examine this issue, the authors use data from the Cambridge Study in Delinquent Development, a prospective longitudinal survey of 411 South London males first studied at age 8 in 1961. Developmental trajectories of criminal activity were defined on the basis of conviction records through age 40, and these were used to predict self-report measures of life failure at age 48 obtained during personal interviews. Results indicate that offending in the first 40 years of life relates to life failure, that childhood risk factors are also implicated in adult life outcomes, and that differences emerge in how offender trajectories predict life failure after controlling for individual and environmental risk factors. This is the first longitudinal investigation to show that chronic offending is associated with life failure into the late 40s, an age period not previously reported, and it also shows that different offending trajectories have different outcomes in late middle age. (Contains 4 tables, 1 figure, and 15 notes.)

This article reports on the influence of neighborhood-level deprivation and collective efficacy on children's antisocial behavior between the ages of 5 and 10 years. Latent growth curve modeling was applied to characterize the developmental course of antisocial behavior among children in the E-Risk Longitudinal Twin Study, an epidemiological cohort of 2,232 children. Children in deprived versus affluent neighborhoods had higher levels of antisocial behavior at school entry (24.1 vs. 20.5, p less than 0.001) and a slower rate of decline from involvement in antisocial behavior between the ages of 5 and 10 (-0.54 vs. -0.78, p less than 0.01). Neighborhood collective efficacy was negatively associated with levels of antisocial behavior at school entry (r = -0.10, p less than 0.01) but only in deprived neighborhoods; this relationship held after controlling for neighborhood problems and family-level factors. Collective efficacy did not predict the rate of change in antisocial behavior between the ages of 5 and 10. Findings suggest that neighborhood collective efficacy may have a protective effect on children living in deprived contexts. (Contains 3 footnotes, 4 tables, and 3 figures.)

This article charts a strategic research course toward an empirical foundation for the diagnosis of conduct disorder in the forthcoming DSM-V. Since the DSM-IV appeared in 1994, an impressive amount of new information about conduct disorder has emerged. As a result of this new knowledge, reasonable rationales have been put forward for adding to the conduct disorder diagnostic protocol: a childhood-limited subtype, family psychiatric history, callous-unemotional traits, female-specific criteria, preschool-specific criteria, early substance use, and biomarkers from genetics, neuroimaging, and physiology research. This article reviews the evidence for these and other potential changes to the conduct disorder diagnosis. We report that although there is a great deal of exciting research into each of the topics, very little of it provides the precise sort of evidence base required to justify any alteration to the DSM-V. We outline specific research questions and study designs needed to build the lacking evidence base for or against proposed changes to DSM-V conduct disorder.

Objective: To study whether behavioral and emotional problems during childhood predicted early sexual debut, risky sex at age 21 years, and sexually transmitted infections up to age 21 years. Some possible mediational pathways were also explored. Method: Participants were enrolled in the Dunedin Multidisciplinary Health and Development Study (n = 1,037), a prospective, longitudinal study of a New Zealand birth cohort born in 1972-1973. Data obtained at ages 5, 7, 9, 11, 13, 15, and 21 years were used. Adjustment was made for gender, socioeconomic status, parenting factors, and residence changes. Results: High levels of antisocial behavior between age 5 and 11 years were associated with increased odds of early sexual debut (adjusted odds ratio [AOR] 2.17, 95% confidence [CI] 1.34-3.54) and risky sex (AOR 1.88, 95% CI 1.04-3.40). No relationship was observed between hyperactivity and later sexual health outcomes. In contrast, high levels of anxiety were associated with reduced odds of risky sex (AOR 0.45, 95%CI 0.25-0.80) and sexually transmitted infections (AOR 0.34, 95% CI0.17-0.70). Involvement with delinquent peers explained some of the association between antisocial behavior and early sexual debut and risky sex. A poor relationship with parents also explained some of the association between antisocial behavior and early sexual debut. Conclusions: The findings demonstrate links between behavioral and emotional problems occurring early in life and later deleterious sexual health outcomes. Targeting antisocial behavior and teaching accurate appraisals of danger during childhood may help mitigate these negative consequences.

Objective: Children who are physically maltreated are at risk of a range of adverse outcomes in childhood and adulthood, but some children who are maltreated manage to function well despite their history of adversity. Which individual, family, and neighborhood characteristics distinguish resilient from non-resilient maltreated children? Do children's individual strengths promote resilience even when children are exposed to multiple family and neighborhood stressors (cumulative stressors model)? Methods: Data were from the Environmental Risk Longitudinal Study which describes a nationally representative sample of 1,116 twin pairs and their families. Families were home-visited when the twins were 5 and 7 years old, and teachers provided information about children's behavior at school. Interviewers rated the likelihood that children had been maltreated based on mothers' reports of harm to the child and child welfare involvement with the family. Results: Resilient children were those who engaged in normative levels of antisocial behavior despite having been maltreated. Boys (but not girls) who had above-average intelligence and whose parents had relatively few symptoms of antisocial personality were more likely to be resilient versus non-resilient to maltreatment. Children whose parents had substance use problems and who lived in relatively high crime neighborhoods that were low on social cohesion and informal social control were less likely to be resilient versus non-resilient to maltreatment. Consistent with a cumulative stressors model of children's adaptation, individual strengths distinguished resilient from non-resilient children under conditions of low, but not high, family and neighborhood stress. Conclusion: These findings suggest that for children residing in multi-problem families, personal resources may not be sufficient to promote their adaptive functioning.

Using prospective data from the Dunedin Multidisciplinary Health and Development Study birth cohort, the authors found that adolescents with low self-esteem had poorer mental and physical health, worse economic prospects, and higher levels of criminal behavior during adulthood, compared with adolescents with high self-esteem. The long-term consequences of self-esteem could not be explained by adolescent depression, gender, or socioeconomic status. Moreover, the findings held when the outcome variables were assessed using objective measures and informant reports; therefore, the findings cannot be explained by shared method variance in self-report data. The findings suggest that low self-esteem during adolescence predicts negative real-world consequences during adulthood.

Gene-environment interplay is a general term that covers several divergent concepts with different meanings and different implications. In this review, we evaluate research evidence on four varieties of gene-environment interplay. First, we consider epigenetic mechanisms by which environmental influences alter the effects of genes. Second, we focus on variations in heritability according to environmental circumstances. Third, we discuss what is known about gene-environment correlations. Finally, we assess concepts and findings on the interaction between specific identified genes and specific measured environmental risks. In order to provide an understanding of what may be involved in gene-environment interplay, we begin our presentation with a brief historical review of prevailing views about the role of genetic and environmental factors in the causation of mental disorders, and we provide a simplified account of some of the key features of how genes "work".

The present study examines the relation between psychopathy and the Big Five dimensions of personality in two samples of adolescents. Specifically, the study tests the hypothesis that the aspect of psychopathy representing selfishness, callousness, and interpersonal manipulation (Factor 1) is most strongly associated with low Agreeableness, whereas the aspect of psychopathy representing impulsivity, instability, and social deviance (Factor 2) is associated with low Agreeableness, low Conscientiousness, and high Neuroticism. Data from 13- and 16-year-old boys and their mothers from two samples of the Pittsburgh Youth Study are used to test these hypotheses. Results were consistent across age and rating source in supporting the initial hypotheses, providing support for the construct of juvenile psychopathy and the interpretation of psychopathy as a constellation of traits drawn from a general model of personality functioning.

Background: Individuals with early warning signs of life-long psychopathy, callous-unemotional traits (CU) and high levels of antisocial behaviour (AB) can be identified in childhood. We report here the first twin study of high levels of psychopathic tendencies in young children. Methods: At the end of the first school year, teachers provided ratings of CU and AB for 3687 twin pairs from the Twins Early Development Study (TEDS). For the analyses of extreme CU, we selected same-sex twin pairs where at least one twin scored 1.3 or more standard deviations above the mean on the CU scale (612 probands, 459 twin pairs). For the analysis of extreme AB, we selected same-sex twin pairs where at least one twin scored 1.3 or more standard deviations above the mean on AB scale (444 probands, 364 twin pairs). Furthermore, the extreme AB sample was divided into those who were also extreme on CU (children with psychopathic tendencies; 234 probands, 187 twin pairs) and those who did not score in the extreme for CU (children without psychopathic tendencies; 210 probands, 177 twin pairs). Results: DeFries-Fulker extremes analysis indicated that exhibiting high levels of CU is under strong genetic influence. Furthermore, separating children with AB into those with high and low levels of CU showed striking results: AB in children with high levels of CU is under extremely strong genetic influence and no influence of shared environment, whereas AB in children with low levels of CU shows moderate genetic and shared environmental influence. Conclusions: The remarkably high heritability for CU, and for AB children with CU, suggests that molecular genetic research on antisocial behaviour should focus on the CU core of psychopathy. Our findings also raise questions for public policy on interventions for antisocial behaviour.

The present study examined patterns of stability and change in loneliness across adolescence. Data were drawn from the Environmental Risk (E-Risk) Longitudinal Twin Study, a UK population-representative cohort of 2,232 individuals born in 1994 and 1995. Loneliness was assessed when participants were aged 12 and 18. Loneliness showed modest stability across these ages (r =.25). Behavioral genetic modeling indicated that stability in loneliness was explained largely by genetic influences (66%), while change was explained by nonshared environmental effects (58%). Individuals who reported loneliness at both ages were broadly similar to individuals who only reported it at age 18, with both groups at elevated risk of mental health problems, physical health risk behaviors, and education and employment difficulties. Individuals who were lonely only at age 12 generally fared better; however, they were still more likely to finish school with lower qualifications. Positive family influences in childhood predicted reduced risk of loneliness at age 12, while negative peer experiences increased the risk. Together, the findings show that while early adolescent loneliness does not appear to exert a cumulative burden when it persists, it is nonetheless a risk for a range of concomitant impairments, some of which can endure. [ABSTRACT FROM AUTHOR]

Research on child effects has demonstrated that children's difficult and coercive behavior provokes harsh discipline from adults. Using a genetically sensitive design, the authors tested the limits of child effects on adult behavior that ranged from the normative (corporal punishment) to the nonnormative (physical maltreatment). The sample was a 1994-1995 nationally representative birth cohort of 1,116 twins and their families who participated in the Environmental Risk Longitudinal Study. Results showed that environmental factors accounted for most of the variation in corporal punishment and physical maltreatment. However, corporal punishment was genetically mediated in part, and the genetic factors that influenced corporal punishment were largely the same as those that influenced children's antisocial behavior, suggesting a child effect. The authors conclude that risk factors for maltreatment are less likely to reside within the child and more likely to reside in characteristics that differ between families.

Society's efforts to deter crime with punishment may be ineffective because those individuals most prone to commit crime often act impulsively, with little thought for the future, and so they may be unmoved by the threat of later punishment. Deterrence messages they receive, therefore, may fall on deaf ears. This article examines this issue by testing the relationship between criminal propensity, perceived risks and costs of punishment, and criminal behavior. The authors analyzed data from the Dunedin (New Zealand) Study, a longitudinal study of individuals from birth through age 26 (N = 1,002). They found that in fact, deterrence perceptions had their greatest impact on criminally prone study members. (Contains 4 tables, 4 figures, and 13 notes.)