Search

Objective: People who eat healthier diets are less likely to develop dementia, but the biological mechanism of this protection is not well understood. We tested the hypothesis that healthy diet protects against dementia because it slows the pace of biological aging. Methods: We analyzed Framingham Offspring Cohort data. We included participants ≥60 years‐old, free of dementia and having dietary, epigenetic, and follow‐up data. We assessed healthy diet as long‐term adherence to the Mediterranean‐Dash Intervention for Neurodegenerative Delay diet (MIND, over 4 visits spanning 1991–2008). We measured the pace of aging from blood DNA methylation data collected in 2005–2008 using the DunedinPACE epigenetic clock. Incident dementia and mortality were defined using study records compiled from 2005 to 2008 visit through 2018. Results: Of n = 1,644 included participants (mean age 69.6, 54% female), n = 140 developed dementia and n = 471 died over 14 years of follow‐up. Greater MIND score was associated with slower DunedinPACE and reduced risks for dementia and mortality. Slower DunedinPACE was associated with reduced risks for dementia and mortality. In mediation analysis, slower DunedinPACE accounted for 27% of the diet‐dementia association and 57% of the diet‐mortality association. Interpretation: Findings suggest that slower pace of aging mediates part of the relationship of healthy diet with reduced dementia risk. Monitoring pace of aging may inform dementia prevention. However, a large fraction of the diet‐dementia association remains unexplained and may reflect direct connections between diet and brain aging that do not overlap other organ systems. Investigation of brain‐specific mechanisms in well‐designed mediation studies is warranted. ANN NEUROL 2024;95:1069–1079 [ABSTRACT FROM AUTHOR]

INTRODUCTION: Dementia risk may be elevated in socioeconomically disadvantaged neighborhoods. Reasons for this remain unclear, and this elevation has yet to be shown at a national population level. METHODS: We tested whether dementia was more prevalent in disadvantaged neighborhoods across the New Zealand population (N = 1.41 million analytic sample) over a 20‐year observation. We then tested whether premorbid dementia risk factors and MRI‐measured brain‐structure antecedents were more prevalent among midlife residents of disadvantaged neighborhoods in a population‐representative NZ‐birth‐cohort (N = 938 analytic sample). RESULTS: People residing in disadvantaged neighborhoods were at greater risk of dementia (HR per‐quintile‐disadvantage‐increase = 1.09, 95% confidence interval [CI]:1.08‐1.10) and, decades before clinical endpoints typically emerge, evidenced elevated dementia‐risk scores (CAIDE, LIBRA, Lancet, ANU‐ADRI, DunedinARB; β's 0.31‐0.39) and displayed dementia‐associated brain structural deficits and cognitive difficulties/decline. DISCUSSION: Disadvantaged neighborhoods have more residents with dementia, and decades before dementia is diagnosed, residents have more dementia‐risk factors and brain‐structure antecedents. Whether or not neighborhoods causally influence risk, they may offer scalable opportunities for primary dementia prevention. [ABSTRACT FROM AUTHOR]

Mapping individual differences in brain function has been hampered by poor reliability as well as limited interpretability. Leveraging patterns of brain‐wide functional connectivity (FC) offers some promise in this endeavor. In particular, a macroscale principal FC gradient that recapitulates a hierarchical organization spanning molecular, cellular, and circuit level features along a sensory‐to‐association cortical axis has emerged as both a parsimonious and interpretable measure of individual differences in behavior. However, the measurement reliabilities of this FC gradient have not been fully evaluated. Here, we assess the reliabilities of both global and regional principal FC gradient measures using test–retest data from the young adult Human Connectome Project (HCP‐YA) and the Dunedin Study. Analyses revealed that the reliabilities of principal FC gradient measures were (1) consistently higher than those for traditional edge‐wise FC measures, (2) higher for FC measures derived from general FC (GFC) in comparison with resting‐state FC, and (3) higher for longer scan lengths. We additionally examined the relative utility of these principal FC gradient measures in predicting cognition and aging in both datasets as well as the HCP‐aging dataset. These analyses revealed that regional FC gradient measures and global gradient range were significantly associated with aging in all three datasets, and moderately associated with cognition in the HCP‐YA and Dunedin Study datasets, reflecting contractions and expansions of the cortical hierarchy, respectively. Collectively, these results demonstrate that measures of the principal FC gradient, especially derived using GFC, effectively capture a reliable feature of the human brain subject to interpretable and biologically meaningful individual variation, offering some advantages over traditional edge‐wise FC measures in the search for brain–behavior associations. [ABSTRACT FROM AUTHOR]

Objectives: Childhood caries is associated with poorer self‐rated general health in adulthood, but it remains unclear whether that holds for physical health and aging. The aim of this study was to identify whether age‐5 caries is associated with (a) biomarkers for poor physical health, and (b) the pace of aging (PoA) by age 45 years. Methods: Participants are members of the Dunedin Multidisciplinary Health and Development Study birth cohort. At age 45, 94.1% (n = 938) of those still alive took part. Data on age‐5 caries experience and age‐45 health biomarkers were collected. The PoA captures age‐related decline across the cardiovascular, metabolic, renal, immune, dental and pulmonary systems from age 26 to 45 years. We used (a) generalized estimating equations to examine associations between age‐5 caries and poor physical health by age 45 years, and (b) ordinary least squares regression to examine whether age‐5 caries was associated with the PoA. Analyses adjusted for sex, perinatal health, childhood SES and childhood IQ. Results: High caries experience at age‐5 was associated with higher risk for some metabolic abnormalities, including BMI ≥30, high waist circumference, and high serum leptin. Those with high caries experience at age‐5 were aging at a faster rate by age 45 years than those who had been caries‐free. Conclusions: Oral health is essential for wellbeing. Poor oral health can be an early signal of a trajectory towards poor health in adulthood. Management for both conditions should be better‐integrated; and integrated population‐level prevention strategies should be foundational to any health system. [ABSTRACT FROM AUTHOR]

Background: Chaotic home environments may contribute to children's attention‐deficit hyperactivity disorder (ADHD) symptoms. However, ADHD genetic risk may also influence household chaos. This study investigated whether children in chaotic households had more ADHD symptoms, if mothers and children with higher ADHD genetic risk lived in more chaotic households, and the joint association of genetic risk and household chaos on the longitudinal course of ADHD symptoms across childhood. Methods: Participants were mothers and children from the Environmental Risk (E‐Risk) Longitudinal Twin Study, a UK population‐representative birth cohort of 2,232 twins. Children's ADHD symptoms were assessed at ages 5, 7, 10 and 12 years. Household chaos was rated by research workers at ages 7, 10 and 12, and by mother's and twin's self‐report at age 12. Genome‐wide ADHD polygenic risk scores (PRS) were calculated for mothers (n = 880) and twins (n = 1,999); of these, n = 871 mothers and n = 1,925 children had information on children's ADHD and household chaos. Results: Children in more chaotic households had higher ADHD symptoms. Mothers and children with higher ADHD PRS lived in more chaotic households. Children's ADHD PRS was associated with household chaos over and above mother's PRS, suggesting evocative gene–environment correlation. Children in more chaotic households had higher baseline ADHD symptoms and a slower rate of decline in symptoms. However, sensitivity analyses estimated that gene–environment correlation accounted for a large proportion of the association of household chaos on ADHD symptoms. Conclusions: Children's ADHD genetic risk was independently associated with higher levels of household chaos, emphasising the active role of children in shaping their home environment. Our findings suggest that household chaos partly reflects children's genetic risk for ADHD, calling into question whether household chaos directly influences children's core ADHD symptoms. Our findings highlight the importance of considering parent and child genetic risk in relation to apparent environmental exposures. [ABSTRACT FROM AUTHOR]

Geriatricians and others must embrace the emerging field of geroscience. Until recently geroscience research was pursued in laboratory animals, but now this field requires specialized expertise in the care of vulnerable older patients with multiple chronic diseases and geriatric syndromes, the population likely to benefit the most from emerging therapies. While chronological aging measures the inevitable passage of clock time that occurs equally for everyone, biological aging varies among individuals, and importantly, it is modifiable. Advances in our understanding of biological aging, the discovery of strategies for modifying its rate, and an appreciation of aging as a shared risk factor for chronic diseases have jointly led to the Geroscience Hypothesis. This hypothesis states that interventions modifying aging biology can slow its progression—resulting in the delay or prevention of the onset of multiple diseases and disorders. Here we wish to report on the Third Geroscience Summit held at National Institutes of Health on November 4–5, 2019, which highlighted the importance of engaging other disciplines including clinicians. Involvement by scientists with expertise in clinical trials, health outcomes research, behavioral and social sciences, health policy, and economics is urgently needed to translate geroscience discoveries from the bench to clinical care and health policy. Adding to the urgency of broadening this geroscience coalition is the emergence of biological aging as one the most important modifiable factors of COVID‐19, combined with the inability of our society to once again recognize and confront aging as a priority and opportunity when facing these types of public health emergencies. [ABSTRACT FROM AUTHOR]

Growing evidence indicates that the defining characteristics of autism spectrum disorder (ASD) are distributed throughout the general population; hence, understanding the correlates of aging in people with high autistic traits could shed light on ASD and aging. 915 members of the Dunedin longitudinal birth cohort completed a measure of autistic traits at age 45. A composite measure of the "pace of aging" was derived by tracking the decline in 19 biomarkers across ages 26, 32, 38, and 45 years. Facial age was also assessed. Reports of perceived health were collected from participants themselves, informants, and interviewers. Higher self‐reported autistic traits significantly correlated with a faster pace of aging, older facial age, and poorer self‐, informant‐, and interviewer‐rated health. After control for sex, SES and IQ, autistic traits were significantly associated with each variable: pace of aging (β = 0.09), facial age (β = 0.08), self‐ (β = −0.15), informant (β = −0.12), and interviewer‐rated (β = −0.17) health. Autistic traits measured at age 45 are associated with faster aging. Participants with high autistic traits appear to be more vulnerable to poor health outcomes, as previously reported for those clinically diagnosed with ASD. Therefore, autistic traits may have important health implications. Replicating these findings in samples of autistic people is needed to identify the mechanism of their effect on aging and physical health to improve outcomes for those with ASD diagnoses or high autistic traits. Lay Summary The role that autistic traits have in relation to health outcomes has not been investigated. We looked at how physical health and aging (measured with self‐reported questions and decline in multiple biological measures) were related to autistic traits (measured with a questionnaire, at age 45). We found that higher autistic traits were associated with poorer reports of physical health, and a faster pace of aging. This suggests that both those with autism and those with higher autistic traits may be more likely to experience poorer health outcomes. [ABSTRACT FROM AUTHOR]

Background: A recent genome‐wide association study identified molecular‐genetic associations with age‐at‐first‐birth. However, the meaning of these genetic discoveries is unclear. Drawing on evidence linking early pregnancy with disinhibitory behavior, we tested the hypothesis that genetic discoveries for age‐at‐first‐birth predict disinhibition. Methods: We included participants with genotype data from the two‐decade‐long Environmental Risk (E‐Risk) Study (N = 1,999) and the four‐decade‐long Dunedin Study (N = 918). We calculated a genome‐wide polygenic score for age‐at‐first‐birth and tested whether it was associated with a range of disinhibitory outcomes across the life course, including low childhood self‐control; risk for externalizing psychopathology; officially recorded criminal offending; substance dependence; informant reports of disinhibitory problems; and number of lifetime sexual partners. We further tested whether associations were attributable to accelerated pubertal maturation. Results: In both cohorts, the age‐at‐first‐birth polygenic score predicted low childhood self‐control, externalizing psychopathology, officially recorded criminal offending, substance dependence, and number of sexual partners. Associations were modest, but robust across replication. Childhood disinhibition partly mediated associations between the polygenic score and reproductive behaviors. In contrast, associations were not attributable to accelerated pubertal timing. Conclusions: Genomic discoveries for age‐at‐first‐birth are about more than reproductive biology: They provide insight into the disinhibitory traits and behaviors that accompany early parenthood. Age‐at‐first‐birth is a useful proxy phenotype for researchers interested in disinhibition. Further, interventions that improve self‐regulation abilities may benefit young parents and their children. [ABSTRACT FROM AUTHOR]

This study tested implications of new genetic discoveries for understanding the association between parental investment and children's educational attainment. A novel design matched genetic data from 860 British mothers and their children with home-visit measures of parenting: the E-Risk Study. Three findings emerged. First, both mothers' and children's education-associated genetics, summarized in a genome-wide polygenic score, were associated with parenting-a gene-environment correlation. Second, accounting for genetic influences slightly reduced associations between parenting and children's attainment-indicating some genetic confounding. Third, mothers' genetics were associated with children's attainment over and above children's own genetics, via cognitively stimulating parenting-an environmentally mediated effect. Findings imply that, when interpreting parents' effects on children, environmentalists must consider genetic transmission, but geneticists must also consider environmental transmission. [ABSTRACT FROM AUTHOR]

What impact does formal punishment have on antisocial conduct—does it deter or promote it? The findings from a long line of research on the labeling tradition indicate formal punishments have the opposite‐of‐intended consequence of promoting future misbehavior. In another body of work, the results show support for deterrence‐based hypotheses that punishment deters future misbehavior. So, which is it? We draw on a nationally representative sample of British adolescent twins from the Environmental Risk (E‐Risk) Longitudinal Twin Study to perform a robust test of the deterrence versus labeling question. We leverage a powerful research design in which twins can serve as the counterfactual for their co‐twin, thereby ruling out many sources of confounding that have likely impacted prior studies. The pattern of findings provides support for labeling theory, showing that contact with the justice system—through spending a night in jail/prison, being issued an anti‐social behaviour order (ASBO), or having an official record—promotes delinquency. We conclude by discussing the impact these findings may have on criminologists' and practitioners' perspective on the role of the juvenile justice system in society. [ABSTRACT FROM AUTHOR]

Objectives: Given that people with higher intelligence have been shown to live longer, enjoy better health and have more favourable health behaviours, we investigated the association between childhood IQ and a range of important dental health and service‐use indicators at age 38. Methods: Long‐standing prospective study of a complete birth cohort, with childhood IQ (assessed at ages 7, 9, 11 and 13 years) used to allocate participants (N = 818) to one of four ordinal categories of childhood IQ. Results: There were distinct and consistent gradients by childhood IQ in almost all of the dental caries experience measures (with the exception of filled teeth) whereby each was most severe in the lowest child IQ category and least severe in the highest; the exception was the mean FT score, for which there was no discernible gradient. Indicators of self‐care and periodontal disease experience showed similar gradients, and multivariate modelling using the continuous IQ score confirmed the observed patterns. Conclusions: Childhood cognitive function is a key determinant of oral health and dental service‐use by midlife, with those of lower cognitive capacity as children likely to have poorer oral health, less favourable oral health‐related beliefs, and more detrimental self‐care and dental visiting practices by age 38. There is a need to shape dental clinical services and public health interventions so that people with the poorest cognitive function do not continue to be disadvantaged. [ABSTRACT FROM AUTHOR]

Background: Childhood risk factors are associated with elevated inflammatory biomarkers in adulthood, but it is unknown whether these risk factors are associated with increased adult levels of the chronic inflammation marker soluble urokinase plasminogen activator receptor (suPAR). We aimed to test the hypothesis that childhood exposure to risk factors for adult disease is associated with elevated suPAR in adulthood and to compare suPAR with the oft‐reported inflammatory biomarker C‐reactive protein (CRP). Methods: Prospective study of a population‐representative 1972–1973 birth cohort; the Dunedin Multidisciplinary Health and Development Study observed participants to age 38 years. Main childhood predictors were poor health, socioeconomic disadvantage, adverse childhood experiences (ACEs), low IQ, and poor self‐control. Main adult outcomes were adulthood inflammation measured as suPAR and high‐sensitivity CRP (hsCRP). Results: Participants with available plasma samples at age 38 were included (N = 837, 50.5% male). suPAR (mean 2.40 ng/ml; SD 0.91) was positively correlated with hsCRP (r 0.15, p < .001). After controlling for sex, body mass index (BMI), and smoking, children who experienced more ACEs, lower IQ, or had poorer self‐control showed elevated adult suPAR. When the five childhood risks were aggregated into a Cumulative Childhood Risk index, and controlling for sex, BMI, and smoking, Cumulative Childhood Risk was associated with higher suPAR (b 0.10; SE 0.03; p = .002). Cumulative Childhood Risk predicted elevated suPAR, after controlling for hsCRP (b 0.18; SE 0.03; p < .001). Conclusions: Exposure to more childhood risk factors was associated with higher suPAR levels, independent of CRP. suPAR is a useful addition to studies connecting childhood risk to adult inflammatory burden. [ABSTRACT FROM AUTHOR]

Background: Children with conduct problems that persist into adulthood are at increased risk for future behavioral, health, and social problems. However, the longer term public service usage among these children has not been fully documented. To aid public health and intervention planning, adult service usage across criminal justice, health care, and social welfare domains is compared among all individuals from a representative cohort who followed different conduct problem trajectories from childhood into adulthood. Methods: Participants are from the Dunedin Multidisciplinary Health and Development Study, a prospective, representative cohort of consecutive births (N = 1,037) from April 1972 to March 1973 in Dunedin, New Zealand. Regression analyses were used to compare levels of public service usage up to age 38, gathered via administrative and electronic medical records, between participants who displayed distinct subtypes of childhood conduct problems (low, childhood‐limited, adolescent‐onset, and life‐course persistent). Results: Children exhibiting life‐course persistent conduct problems used significantly more services as adults than those with low levels of childhood conduct problems. Although this group comprised only 9.0% of the population, they accounted for 53.3% of all convictions, 15.7% of emergency department visits, 20.5% of prescription fills, 13.1% of injury claims, and 24.7% of welfare benefit months. Half of this group (50.0%) also accrued high service use across all three domains of criminal justice, health, and social welfare services, as compared to only 11.3% of those with low conduct problems (OR = 7.27, 95% CI = 4.42–12.0). Conclusions: Conduct problems in childhood signal high future costs in terms of service utilization across multiple sectors. Future evaluations of interventions aimed at conduct problems should also track potential reductions in health burden and service usage that stretch into midlife. [ABSTRACT FROM AUTHOR]

Abstract: Aims: This study tested whether adolescents who used cannabis or met criteria for cannabis dependence showed neuropsychological impairment prior to cannabis initiation and neuropsychological decline from before to after cannabis initiation. Design: A longitudinal co‐twin control study. Setting and Participants: Participants were 1989 twins from the Environmental Risk (E‐Risk) Longitudinal Twin Study, a nationally representative birth cohort of twins born in England and Wales from 1994 to 1995. Measurements: Frequency of cannabis use and cannabis dependence were assessed at age 18. Intelligence quotient (IQ) was obtained at ages 5, 12 and 18. Executive functions were assessed at age 18. Findings: Compared with adolescents who did not use cannabis, adolescents who used cannabis had lower IQ in childhood prior to cannabis initiation and lower IQ at age 18, but there was little evidence that cannabis use was associated with IQ decline from ages 12–18. For example, adolescents with cannabis dependence had age 12 and age 18 IQ scores that were 5.61 (t = −3.11, P = 0.002) and 7.34 IQ points (t = −5.27, P < 0.001) lower than adolescents without cannabis dependence, but adolescents with cannabis dependence did not show greater IQ decline from age 12–18 (t = −1.27, P = 0.20). Moreover, adolescents who used cannabis had poorer executive functions at age 18 than adolescents who did not use cannabis, but these associations were generally not apparent within twin pairs. For example, twins who used cannabis more frequently than their co‐twin performed similarly to their co‐twin on five of six executive function tests (Ps > 0.10). The one exception was that twins who used cannabis more frequently than their co‐twin performed worse on one working memory test (Spatial Span reversed; β = −0.07, P = 0.036). Conclusions: Short‐term cannabis use in adolescence does not appear to cause IQ decline or impair executive functions, even when cannabis use reaches the level of dependence. Family background factors explain why adolescent cannabis users perform worse on IQ and executive function tests. [ABSTRACT FROM AUTHOR]

Therapies to extend healthspan are poised to move from laboratory animal models to human clinical trials. Translation from mouse to human will entail challenges, among them the multifactorial heterogeneity of human aging. To inform clinical trials about this heterogeneity, we report how humans' pace of biological aging relates to personal-history characteristics. Because geroprotective therapies must be delivered by midlife to prevent age-related disease onset, we studied young-adult members of the Dunedin Study 1972-73 birth cohort ( n = 954). Cohort members' Pace of Aging was measured as coordinated decline in the integrity of multiple organ systems, by quantifying rate of decline across repeated measurements of 18 biomarkers assayed when cohort members were ages 26, 32, and 38 years. The childhood personal-history characteristics studied were known predictors of age-related disease and mortality, and were measured prospectively during childhood. Personal-history characteristics of familial longevity, childhood social class, adverse childhood experiences, and childhood health, intelligence, and self-control all predicted differences in cohort members' adulthood Pace of Aging. Accumulation of more personal-history risks predicted faster Pace of Aging. Because trials of anti-aging therapies will need to ascertain personal histories retrospectively, we replicated results using cohort members' retrospective personal-history reports made in adulthood. Because many trials recruit participants from clinical settings, we replicated results in the cohort subset who had recent health system contact according to electronic medical records. Quick, inexpensive measures of trial participants' early personal histories can enable clinical trials to study who volunteers for trials, who adheres to treatment, and who responds to anti-aging therapies. [ABSTRACT FROM AUTHOR]

Background: Adverse childhood experiences (ACEs; e.g. abuse, neglect, and parental loss) have been associated with increased risk for later-life disease and dysfunction using adults’ retrospective self-reports of ACEs. Research should test whether associations between ACEs and health outcomes are the same for prospective and retrospective ACE measures. Methods: We estimated agreement between ACEs prospectively recorded throughout childhood (by Study staff at Study member ages 3, 5, 7, 9, 11, 13, and 15) and retrospectively recalled in adulthood (by Study members when they reached age 38), in the population-representative Dunedin cohort (N = 1,037). We related both retrospective and prospective ACE measures to physical, mental, cognitive, and social health at midlife measured through both objective (e.g. biomarkers and neuropsychological tests) and subjective (e.g. self-reported) means. Results: Dunedin and U.S. Centers for Disease Control ACE distributions were similar. Retrospective and prospective measures of adversity showed moderate agreement (r = .47, p < .001; weighted Kappa = .31, 95% CI: .27–.35). Both associated with all midlife outcomes. As compared to prospective ACEs, retrospective ACEs showed stronger associations with life outcomes that were subjectively assessed, and weaker associations with life outcomes that were objectively assessed. Recalled ACEs and poor subjective outcomes were correlated regardless of whether prospectively recorded ACEs were evident. Individuals who recalled more ACEs than had been prospectively recorded were more neurotic than average, and individuals who recalled fewer ACEs than recorded were more agreeable. Conclusions: Prospective ACE records confirm associations between childhood adversity and negative life outcomes found previously using retrospective ACE reports. However, more agreeable and neurotic dispositions may, respectively, bias retrospective ACE measures toward underestimating the impact of adversity on objectively measured life outcomes and overestimating the impact of adversity on self-reported outcomes. Associations between personality factors and the propensity to recall adversity were extremely modest and warrant further investigation. Risk predictions based on retrospective ACE reports should utilize objective outcome measures. Where objective outcome measurements are difficult to obtain, correction factors may be warranted. [ABSTRACT FROM AUTHOR]

Background Labour market disengagement among youths has lasting negative economic and social consequences, yet is poorly understood. We compared four types of work-related self-perceptions, as well as vulnerability to mental health and substance abuse problems, among youths not in education, employment or training ( NEET) and among their peers. Methods Participants were from the Environmental Risk (E-Risk) longitudinal study, a nationally representative UK cohort of 2,232 twins born in 1994-1995. We measured commitment to work, job-search effort, professional/technical skills, 'soft' skills (e.g. teamwork, decision-making, communication), optimism about getting ahead, and mental health and substance use disorders at age 18. We also examined childhood mental health. Results At age 18, 11.6% of participants were NEET. NEET participants reported themselves as committed to work and searching for jobs with greater diligence than their non- NEET peers. However, they reported fewer 'soft' skills (B = −0.98, p < .001) and felt less optimistic about their likelihood of getting ahead in life (B = −2.41, p < .001). NEET youths also had higher rates of concurrent mental health and substance abuse problems, but these did not explain the relationship with work-related self-perceptions. Nearly 60% of NEET (vs. 35% of non- NEET) youths had already experienced ≥1 mental health problem in childhood/adolescence. Associations of NEET status with concurrent mental health problems were independent of pre-existing mental health vulnerability. Conclusions Our findings indicate that while NEET is clearly an economic and mental health issue, it does not appear to be a motivation issue. Alongside skills, work-related self-perceptions and mental health problems may be targets for intervention and service provision among this high-risk population. [ABSTRACT FROM AUTHOR]

Aim The aim of the study was to examine the association between telomere erosion and periodontitis in a long-standing prospective cohort study of New Zealand adults. Specific hypotheses tested were as follows: (i) that exposure to periodontitis at ages 26 and 38 was associated with accelerated leucocyte telomere erosion and (ii) that accelerated leucocyte telomere erosion was associated with higher rates of periodontitis by ages 26 and 38. Materials and Methods Periodontal attachment loss data were collected at ages 26 and 38. Blood samples taken at the same ages were analysed to obtain estimates of leucocyte telomere length and erosion over a 12-year period. Results Overall, the mean telomere length was reduced by 0.15 T/S ratio (adjusted) from age 26 to 38 among the 661 participants reported on here. During the same period, the mean attachment loss increased by 10%, after adjusting for sex, socio-economic status and smoking. Regression models showed that attachment loss did not predict telomere length, and that telomere erosion did not predict attachment loss. Conclusions Although both periodontitis and telomere length are age-dependent, they do not appear to be linked, suggesting that determination of leucocyte telomere length may not be a promising clinical approach at this age for identifying people who are at risk for periodontitis. [ABSTRACT FROM AUTHOR]

The aim of this study was to disentangle pervasive from situational antisocial behaviors using multiple informants, and to investigate their genetic and environmental etiologies in preadolescence and across time. Antisocial behaviors were assessed in 2,232 twins from the Environmental Risk (E-Risk) Longitudinal Twin Study at ages 5 and 12. Pervasive antisocial behaviors were defined as behaviors that mothers, teachers, interviewers, and twins themselves agreed on. Results from a psychometric model indicated that the variation in children's pervasive antisocial behaviors was mostly accounted for by familial influences that originated in childhood, whereas situational behaviors were explained by newly emerging nonshared environmental and genetic influences. This study shows that children's pervasive and situational antisocial behaviors have distinct etiologies that could guide research and treatment. [ABSTRACT FROM AUTHOR]

Background The presence of callous-unemotional ( CU) traits designates an important subgroup of antisocial youth at risk for severe, persistent, and impairing conduct problems. As a result, the fifth revision of the Diagnostic and Statistical Manual includes a specifier for youth meeting diagnostic criteria for Conduct Disorder who show elevated CU traits. The current study evaluated the DSM-5 criteria using Item Response Theory ( IRT) analyses and evaluated two methods for using a self-report measure of CU traits to make this diagnosis. Methods The sample included 2257 adolescent ( M age = 15.64, SD = 1.69 years) boys (53%) and girls (47%) from community and incarcerated settings in the United States and the European countries of Belgium, Germany, and Cyprus. Results IRT analyses suggested that four- or eight-item sets from the self-report measure (comparable to the symptoms used by the DSM-5 specifier) provided good model fit, suggesting that they assess a single underlying CU construct. Further, the most stringent method of scoring the self-report scale (i.e. taking only the most extreme responses) to approximate symptom presence provided the best discrimination in IRT analyses, showed reasonable prevalence rates of the specifier, and designated community adolescents who were highly antisocial, whereas the less stringent method best discriminated detained youth. Conclusions Refined self-report scales developed on the basis of IRT findings provided good assessments of most of the symptoms used in the DSM-5 criteria. These scales may be used as one component of a multimethod assessment of the 'With Limited Prosocial Emotions' specifier for Conduct Disorder. [ABSTRACT FROM AUTHOR]

Background The creation of economically mixed communities has been proposed as one way to improve the life outcomes of children growing up in poverty. However, whether low-income children benefit from living alongside more affluent neighbors is unknown. Method Prospectively gathered data on over 1,600 children from the Environmental Risk (E-Risk) Longitudinal Twin Study living in urban environments is used to test whether living alongside more affluent neighbors (measured via high-resolution geo-spatial indices) predicts low-income children's antisocial behavior (reported by mothers and teachers at the ages of 5, 7, 10, and 12). Results Results indicated that low-income boys (but not girls) surrounded by more affluent neighbors had higher levels of antisocial behavior than their peers embedded in concentrated poverty. The negative effect of growing up alongside more affluent neighbors on low-income boys' antisocial behavior held across childhood and after controlling for key neighborhood and family-level factors. Conclusions Findings suggest that efforts to create more economically mixed communities for children, if not properly supported, may have iatrogenic effects on boys' antisocial behavior. [ABSTRACT FROM AUTHOR]

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. Ann Neurol 2015;77:607-617 [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Pulling back the curtain on heritability studies: Biosocial criminology in the postgenomic era" by Callie H. Burt and Ronald L. Simons in the volume 52, 2014 issue.

Objective The Global Burden of Disease Study 2010 (GBD 2010) is the first to include conduct disorder (CD) and attention-deficit/hyperactivity disorder (ADHD) for burden quantification. Method A previous systematic review pooled the available epidemiological data for CD and ADHD, and predicted prevalence by country, region, age and sex for each disorder. Prevalence was then multiplied by a disability weight to calculate years lived with disability (YLDs). As no evidence of deaths resulting directly from either CD or ADHD was found, no years of life lost (YLLs) were calculated. Therefore, the number of disability-adjusted life years (DALYs) was equal to that of YLDs. Results Globally, CD was responsible for 5.75 million YLDs/DALYs with ADHD responsible for a further 491,500. Collectively, CD and ADHD accounted for 0.80% of total global YLDs and 0.25% of total global DALYs. In terms of global DALYs, CD was the 72nd leading contributor and among the 15 leading causes in children aged 5-19 years. Between 1990 and 2010, global DALYs attributable to CD and ADHD remained stable after accounting for population growth and ageing. Conclusions The global burden of CD and ADHD is significant, particularly in male children. Appropriate allocation of resources to address the high morbidity associated with CD and ADHD is necessary to reduce global burden. However, burden estimation was limited by data lacking for all four epidemiological parameters and by methodological challenges in quantifying disability. Future studies need to address these limitations in order to increase the accuracy of burden quantification. [ABSTRACT FROM AUTHOR]

Background: Improving cardiovascular fitness has been promoted as a promising nonpharmacological strategy for buffering against age‐related cognitive decline and mitigating risk for Alzheimer's disease and related dementia (ADRD). These beneficial effects may be related to the capacity for improved cardiovascular fitness to stave off age‐related brain atrophy. However, there is evidence that some neurological benefits associated with adult cardiovascular fitness may be better explained by early childhood factors—referred to as neuroselection—rather than any active neuroprotective effects of fitness on the brain. Method: Data from 875 participants from the population‐representative Dunedin Study were utilized to investigate associations between cardiovascular fitness (VO2Max) at age 45, changes in cardiovascular fitness across adulthood, and structural brain integrity (cortical thickness, surface area, and subcortical grey matter volume) at age 45. Critically, the potential confounding effects of childhood IQ on any observed associations in midlife were evaluated in order to disentangle potential neuroselective from neuroprotective effects. Result: Better VO2Max at age 45 was associated with thicker cortex in frontal and temporal lobes (βs:0.14 to 0.25, Figure 1b) and smaller hippocampal fissure volumes at age 45 (β=‐0.18). Higher rates of decline in VO2max were associated with lower total (β=‐0.11) and distributed regional (βs:‐0.11 to ‐0.19, Figure 2b) surface area at age 45. These associations were unaffected by the inclusion of childhood IQ in the analyses. Conclusion: Better midlife cardiovascular fitness may offer neuroprotective effects on brain structure, which may in turn mitigate ADRD risk and buffer against cognitive decline. [ABSTRACT FROM AUTHOR]

Background: Children growing up in poor versus affluent neighborhoods are more likely to spend time in prison, develop health problems and die at an early age. The question of how neighborhood conditions influence our behavior and health has attracted the attention of public health officials and scholars for generations. Online tools are now providing new opportunities to measure neighborhood features and may provide a cost effective way to advance our understanding of neighborhood effects on child health. Method: A virtual systematic social observation (SSO) study was conducted to test whether Google Street View could be used to reliably capture the neighborhood conditions of families participating in the Environmental-Risk (E-Risk) Longitudinal Twin Study. Multiple raters coded a subsample of 120 neighborhoods and convergent and discriminant validity was evaluated on the full sample of over 1,000 neighborhoods by linking virtual SSO measures to: (a) consumer based geo-demographic classifications of deprivation and health, (b) local resident surveys of disorder and safety, and (c) parent and teacher assessments of children's antisocial behavior, prosocial behavior, and body mass index. Results: High levels of observed agreement were documented for signs of physical disorder, physical decay, dangerousness and street safety. Inter-rater agreement estimates fell within the moderate to substantial range for all of the scales (ICCs ranged from .48 to .91). Negative neighborhood features, including SSO-rated disorder and decay and dangerousness corresponded with local resident reports, demonstrated a graded relationship with census-defined indices of socioeconomic status, and predicted higher levels of antisocial behavior among local children. In addition, positive neighborhood features, including SSO-rated street safety and the percentage of green space, were associated with higher prosocial behavior and healthy weight status among children. Conclusions: Our results support the use of Google Street View as a reliable and cost effective tool for measuring both negative and positive features of local neighborhoods. [ABSTRACT FROM AUTHOR]

Shearer DM, Thomson WM, Caspi A, Moffitt TE, Broadbent JM, Poulton R. Family history and oral health: findings from the Dunedin Family History Study. Community Dent Oral Epidemiol 2011. © 2011 John Wiley & Sons A/S Abstract - Context: The effects of the oral health status of one generation on that of the next within families are unclear. Objectives: To determine whether parental oral health history is a risk factor for oral disease. Methods: Oral examination and interview data were collected during the age-32 assessments in the Dunedin Study. Parental data were also collected on this occasion. The sample was divided into two familial-risk groups for caries/tooth loss (high risk and low risk) based on parents' self-reported history of tooth loss at the age-32 assessment interview. Main outcome measures: Probands' dental caries and tooth loss status at age 32, together with lifelong dental caries trajectory (age 5-32). Results: Caries/tooth loss risk analysis was conducted for 640 proband-parent groups. Reference groups were the low-familial-risk groups. After controlling for confounding factors (sex, episodic use of dental services, socio-economic status and plaque trajectory), the prevalence ratio (PR) for having lost 1+ teeth by age 32 for the high-familial-risk group was 1.41 [95% confidence interval (CI) 1.05, 1.88] and the rate ratio for DMFS at age 32 was 1.41 (95% CI 1.24, 1.60). In the high-familial-risk group, the PR of following a high caries trajectory was 2.05 (95% CI 1.37, 3.06). Associations were strongest when information was available about both parents' oral health. Nonetheless, when information was available for one parent only, associations were significant for some outcomes. Conclusions: People with poor oral health tend to have parents with poor oral health. Family/parental history of oral health is a valid representation of the intricacies of the shared genetic and environmental factors that contribute to an individual's oral health status. Associations are strongest when data from both parents can be obtained. [ABSTRACT FROM AUTHOR]

Background: Theory of mind (ToM) allows the understanding and prediction of other people's behaviours based on their mental states (e.g. beliefs). It is important for healthy social relationships and thus may contribute towards children's involvement in bullying. The present study investigated whether children involved in bullying during early adolescence had poor ToM in childhood. Method: Participants were members of the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative sample of 2,232 children and their families. We visited families when children were 5, 7, 10 and 12 years. ToM was assessed when the children were 5 years using eight standardized tasks. Identification of those children who were involved in bullying as victims, bullies and bully-victims using mothers', teachers' and children's reports was carried out when they were 12 years' old. Results: Poor ToM predicted becoming a victim (effect size, d = 0.26), bully ( d = 0.25) or bully-victim ( d = 0.44) in early adolescence. These associations remained for victims and bully-victims when child-specific (e.g. IQ) and family factors (e.g. child maltreatment) were controlled for. Emotional and behavioural problems during middle childhood did not modify the association between poor ToM and adolescent bullying experiences. Conclusion: Identifying and supporting children with poor ToM early in life could help reduce their vulnerability for involvement in bullying and thus limit its adverse effects on mental health. [ABSTRACT FROM AUTHOR]

Thomson WM, Caspi A, Poulton R, Moffitt TE, Broadbent JM. Personality and oral health. Eur J Oral Sci 2011; 119: 366-372. © 2011 Eur J Oral Sci We investigated age-26 personality characteristics and age-32 oral health in a prospective study of a complete birth cohort born in Dunedin, New Zealand. Personality was measured using the Multidimensional Personality Questionnaire (MPQ). Oral health was measured using the short-form Oral Health Impact Profile (OHIP-14), a global measure, and dental examinations. Personality profiles were constructed for 916 individuals (50.8% men) using standardized MPQ scores, and multivariate analyses examined their association with oral health. Those reporting 1+ OHIP-14 impacts had higher Negative Emotionality scores (and lower Constraint and Positive Emotionality MPQ superfactor scores) than those who did not. After controlling for gender, clinical status, and the other two MPQ superfactors, those scoring higher on Negative Emotionality had a greater risk of reporting 1+ OHIP-14 impacts, as well as 3+ OHIP-14 impacts and worse-than-average oral health. They also had a greater risk of having lost at least one tooth from caries and of having 3+ decayed surfaces. Personality characteristics appear to shape self-reports of oral health. Personality is also a risk factor for clinical disease status, at least with respect to dental caries and its sequelae. Because the attitudes and values tapped into by personality tests can be altered by brief cognitive interventions, those might be useful in preventive dentistry. [ABSTRACT FROM AUTHOR]

Objective: To determine whether parental periodontal disease history is a risk factor for periodontal disease in adult offspring. Methods: Proband periodontal examination [combined attachment loss (CAL) at age 32, and incidence of CAL from ages 26 to 32] and interview data were collected during the age-32 assessments in the Dunedin Study. Parental data were also collected. The sample was divided into two familial-risk groups for periodontal disease (high- and low-risk) based on parents' self-reported periodontal disease. Results: Periodontal risk analysis involved 625 proband-parent(s) groups. After controlling for confounding factors, the high-familial-risk periodontal group was more likely to have 11 sites with 41mm CAL [relative risk (RR) 1.45; 95% confidence interval (CI) 1.11--1.88], 21 sites with 41mm CAL (RR 1.45; 95% CI 1.03--2.05), 11 sites with 51mm CAL (RR 1.60; 95% CI 1.02--2.50), and 11 sites with 31mm incident CAL (RR 1.64; 95% CI 1.01--2.66) than the low-familial-risk group. Predictive validity was enhanced when information was available from both parents. Conclusions: Parents with poor periodontal health tend to have offspring with poor periodontal health. Family/parental history of oral health is a valid representation of the shared genetic and environmental factors that contribute to an individual's periodontal status, and may help to predict patient prognosis and preventive treatment need. [ABSTRACT FROM AUTHOR]

Background: Bullied children are at risk for later emotional and behavioural problems. ‘Resilient’ children function better than would be expected given their experience of bullying victimisation. This study examined the role of families in promoting resilience following bullying victimisation in primary school. Method: Data were from the Environmental Risk (E-Risk) Study which describes a nationally representative sample of 1,116 twin pairs and their families. We used mothers’ and children’s reports to examine bullying victimisation during primary school and mothers’ and teachers’ reports to measure children’s emotional and behavioural adjustment at ages 10 and 12. We used mothers’ and interviewers’ reports to derive measures of protective factors in the home including maternal warmth, sibling warmth and positive atmosphere at home. Results: Results from linear regression models showed that family factors were associated with children’s resilience to bullying victimisation. Maternal warmth, sibling warmth and a positive atmosphere at home were particularly important in bullied children compared to non-bullied children in promoting emotional and behavioural adjustment. We used a twin differences design to separate out environmental protective factors in twins who are genetically identical. Differences in maternal warmth between twins from genetically identical monozygotic pairs concordant for bullying victimisation were correlated with twin differences in behavioural problems ( r = –.23) such that the twin who received the most warmth had fewer behavioural problems. This shows that maternal warmth has an environmental effect in protecting children from the negative outcomes associated with being bullied. Conclusions: Warm family relationships and positive home environments help to buffer children from the negative outcomes associated with bullying victimisation. Warm parent–child relationships can exert an environmentally mediated effect on children’s behavioural adjustment following bullying victimisation. Identifying protective factors that promote resilience to bullying victimisation could lead to improved intervention strategies targeting the home environment. [ABSTRACT FROM AUTHOR]

This prospective longitudinal study examined whether early childhood risk factors contributed to explaining and predicting intimate partner violence (IPV) in midadulthood. Participants included 202 men from the Cambridge longitudinal study who were in an intimate relationship in their mid-40s. Neuropsychological deficits and the presence of a criminogenic family environment were measured between ages 8 and 10. Antisocial behavior was measured between ages 8 and 18. IPV was measured at age 48 using a self-report instrument completed by the participants' female partners. Perpetration and victimization rates were relatively high; violence was mostly mutual, and men were more likely to be victims than perpetrators. Findings indicate that a criminogenic environment increases the risk of IPV by fostering the development of antisocial behavior and neuropsychological deficits. A link also exists between a high level of antisocial behavior during adolescence and the risk of IPV later in life. The results suggest the presence of both continuity and discontinuity of antisocial behavior as childhood risk factors that increase the likelihood of future involvement in IPV, but the role of these risk factors is modest. [ABSTRACT FROM AUTHOR]

The objective of the study was to examine the link between anxiety and allergies to establish whether it reflects a psychobiological reality or a possible methodological bias. A cohort of 1,037 children enrolled in the study. Anxiety disorders were assessed between 11 and 21 years. Anxious personality was assessed at 18 years. Allergies were examined at 21 years by (a) self reports, (b) skin pricks, and (c) serum total immunoglobulin E (IgE). Self-reported allergies were predicted by recurrent anxiety disorders (OR [95% CI]=1.56 [1.06–2.30], p=.023) and self-reports of anxious personality (OR [95% CI]=1.67 [1.17–2.37], p=.004): Objectively verified allergies were not. These results suggest that the link between anxiety and allergies may reflect a methodological artifact rather than a psychobiological reality. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Three groups of children are involved in bullying: victims, bullies and bully-victims who are both bullies and victims of bullying. Understanding the origins of these groups is important since they have elevated emotional and behavioural problems, especially the bully-victims. No research has examined the genetic and environmental influences on these social roles. Method: Mother and teacher reports of victimisation and bullying were collected in a nationally representative cohort of 1,116 families with 10-year-old twins. Model-fitting was used to examine the relative influence of genetics and environments on the liability to be a victim, a bully or a bully-victim. Results: Twelve percent of children were severely bullied as victims, 13% were frequent bullies, and 2.5% were heavily involved as bully-victims. Genetic factors accounted for 73% of the variation in victimisation and 61% of the variation in bullying, with the remainder explained by environmental factors not shared between the twins. The covariation between victim and bully roles ( r = .25), which characterises bully-victims, was accounted for by genetic factors only. Some genetic factors influenced both victimisation and bullying, although there were also genetic factors specific to each social role. Conclusions: Children's genetic endowments, as well as their surrounding environments, influence which children become victims, bullies and bully-victims. Future research identifying mediating characteristics that link the genetic and environmental influences to these social roles could provide targets for intervention. [ABSTRACT FROM AUTHOR]

A previous finding from our group indicated that teacher-rated antisocial behaviour (AB) among 7-year-olds is particularly heritable in the presence of callous-unemotional (CU) traits. Using a sample of 1865 same-sex twin pairs, we employed DeFries-Fulker extremes analysis to investigate whether teacher-rated AB with/without CU traits also shows aetiological differences among 9-year-olds. Furthermore, we assessed whether the differences in the magnitude of heritability would be evident even when hyperactive symptoms were controlled for in the statistical analysis. AB among 9-year-olds was more heritable with than without concomitant CU. The heritability difference was even more pronounced in magnitude when hyperactive symptoms were controlled. CU traits thus appear to index one valid way of sub-typing children with early-onset AB. [ABSTRACT FROM AUTHOR]

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’. [ABSTRACT FROM AUTHOR]

Previous studies have reported, but not explained, the reason for a robust association between reading achievement and antisocial behavior. This association was investigated using the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative 1994-1995 birth cohort of 5- and 7-year-olds. Results showed that the association resulted primarily from environmental factors common to both reading and antisocial behavior and was stronger in boys. Environmental factors also explained the relation between reading disability and conduct disorder. Leading candidate environmental risk factors weakly mediated the association. For boys the best explanation was a reciprocal causation model: poor reading led to antisocial behavior, and vice versa. In contrast, the relation between reading achievement and attention deficit hyperactivity disorder was best explained by common genetic influences. [ABSTRACT FROM AUTHOR]

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.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).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.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. [ABSTRACT FROM AUTHOR]

In this study of the origins of individual differences in theory of mind (ToM), the Environmental Risk (E-Risk) Longitudinal Twin Study sample of 1,116 sixty-month-old twin pairs completed a comprehensive battery of ToM tasks. Individual differences in ToM were striking and strongly associated with verbal ability. Behavioral genetic models of the data showed that environmental factors explained the majority of the variance in ToM performance in this sample. Shared environmental influences on verbal ability had a common impact on ToM and explained more than half the phenotypic correlation between these two skills. Possible underlying proximal mechanisms are discussed, including maternal speech and mind-mindedness, sibling interactions, and peer influences. [ABSTRACT FROM AUTHOR]

Little is known about the extent to which minor self-harm in the general population is associated with psychiatric disorder. A population-based sample of 980 young adults was interviewed independently about past-year suicidal and self-harm behavior and thoughts, and psychiatric disorders. Self-harm included self-harmful behaviors such as self-battery, as well as traditional methods of suicide (ICD [International Classification of Diseases] self-harm). All with ICD self-harm and most with other self-harmful behavior met the criteria for DSM-IV disorder. Suicidal/self-harmful thoughts increased the odds for self-harm, even in men without psychiatric disorder (odds ratio 4.9, 95% confidence interval 1.3-17.9). Young adults engaging in even minor self-harm warrant screening for psychiatric disorder. [ABSTRACT FROM AUTHOR]

Some children exposed to socioeconomic (SES) deprivation are resilient and function better than expected, given the level of deprivation they have experienced. The present study tested genetic and environmental contributions to young children's resilience and vulnerability to SES deprivation. Children's resilience was assessed by the difference between their actual score and the score predicted by their level of SES deprivation in the E-Risk Study, an epidemiological cohort of 1,116 five-year-old twin pairs. Consistent with previous research, results showed that maternal warmth, stimulating activities, and children's outgoing temperament appeared to promote positive adjustment in children exposed to SES deprivation. Findings add new information by demonstrating that resilience is partly heritable and that protective processes operate through both genetic and environmental effects. [ABSTRACT FROM AUTHOR]

Background: Although there is an extensive literature, both speculative and empirical, on postulated differences between males and females in their rates of particular types of disorder, very little is known about the mechanisms that underlie these sex differences. The study of mechanisms is important because it may provide clues on aetiological processes. The review seeks to outline what is known, what are the methodological hazards that must be dealt with, and the research strategies that may be employed. Methods: We note the need for representative general samples, and for adequate measurement and significance testing if valid conclusions are to be drawn. We put forward three levels of causes that have to be considered: a genetically determined distal basic starting point; the varied consequences of being male or female; and the proximal risk or protective factors that are more directly implicated in the causal mechanisms that predispose to psychopathology. In delineating these, we argue that three key sets of evidential criteria have to be met: a) that the risk factors differ between males and females; b) that they provide for risk or protection within each sex; and c) that when introduced into a causal model, they eliminate or reduce the sex differences in the disorders being studied. Results: A male excess mainly applies to early onset disorders that involve some kind of neurodevelopmental impairment. A female excess mainly applies to adolescent-onset emotional disorders. No variables have yet met all the necessary criteria but some good leads are available. The possible research strategies that may be employed are reviewed. Conclusions: The systematic investigation of sex differences constitutes an invaluable tool for the study of the causal processes concerned with psychopathology. [ABSTRACT FROM AUTHOR]

Background: Early childhood antisocial behaviour is a strong prognostic indicator for poor adult mental health. Thus, information about its etiology is needed. Genetic etiology is unknown because most research with young children focuses on environmental risk factors, and the few existing studies of young twins used only mothers' reports of behaviour, which may be biased. Method: We investigated genetic influences on antisocial behaviour in a representative-plus-high-risk sample of 1116 pairs of 5-year-old twins using data from four independent sources: mothers, teachers, examiner-observers previously unacquainted with the children, and the children themselves. Results: Children's antisocial behaviour was reliably measured by all four informants; no bias was detected in mothers', teachers', examiners', or children's reports. Variation in antisocial behaviour that was agreed upon by all informants, and thus was pervasive across settings, was influenced by genetic factors (82%) and experiences specific to each child (18%). Variation in antisocial behaviour that was specific to each informant was meaningful variation, as it was also influenced by genetic factors (from 33% for the children's report to 71% for the teachers' report). Conclusions: This study and four others of very young twins show that genetic risks contribute strongly to population variation in antisocial behaviour that emerges in early childhood. In contrast, genetic risk is known to be relatively modest for adolescent antisocial behaviour, suggesting that the early-childhood form has a distinct etiology, particularly if it is pervasive across situations. [ABSTRACT FROM AUTHOR]

We observed 1,000 3-year-old children who exhibited five temperament types: Undercontrolled, Inhibited, Confident, Reserved, and Well-adjusted. Twenty-three years later, we reexamined 96% of the children as adults, using multiple methods of comprehensive personality assessment, including both self- and informant-reports. These longitudinal data provide the longest and strongest evidence to date that children's early-emerging behavioral styles can foretell their characteristic behaviors, thoughts, and feelings as adults, pointing to the foundations of the human personality in the early years of life. [ABSTRACT FROM AUTHOR]

Background: Previous studies that have examined the long-term effects of infertility and assisted reproductive technology on parenting and child behaviour in families with twins have suffered from methodological problems. This study compared measures of parental adjustment, parenting and child behaviour in families with 5-year-old twins who were conceived after in vitro fertilisation (IVF) or ovulation induction (OI) with families whose twins were naturally conceived (NC). Methods: The families who conceived via IVF/OI ( N=121) were identified from an epidemiological study of twins and matched to families who were conceived naturally ( N=121) on the basis of eleven child and family variables. Mothers were interviewed in their homes for the study. Results: No significant differences were observed between the IVF/OI families and the NC families on measures of parental adjustment or parent and teacher ratings of the twins' behaviour. IVF/OI mothers and their partners agreed with each other about discipline more than NC couples, but otherwise no other differences in parenting were found. Conclusions: Overall, this study provides evidence that families who conceive twins following IVF/OI are functioning well and that the experience of fertility treatment does not lead to long-term difficulties for parents or children. [ABSTRACT FROM AUTHOR]

The salutary effects of being raised by two married, biological parents depend on the quality of care parents can provide. Using data from an epidemiological sample of 1,116 5-year-old twin pairs and their parents, this study found that the less time fathers lived with their children, the more conduct problems their children had, but only if the fathers engaged in low levels of antisocial behavior. In contrast, when fathers engaged in high levels of antisocial behavior, the more time they lived with their children, the more conduct problems their children had. Behavioral genetic analyses showed that children who resided with antisocial fathers received a "double whammy" of genetic and environmental risk for conduct problems. Marriage may not be the answer to the problems faced by some children living in single-parent families unless their fathers can become reliable sources of emotional and economic support. [ABSTRACT FROM AUTHOR]

The present study examined the influence of stable personality traits on romantic relationships using longitudinal data on a large, representative sample of young adults. Relationship experiences (quality, conflict, and abuse) showed relatively small mean-level changes over time and significant levels of rank-order stability, even across different relationship partners. Antecedent personality traits (assessed at age 18) predicted relationship experiences at age 26 and change in relationship experiences from age 21 to 26. Conversely, relationship experiences also predicted change in personality. Importantly, these findings generally held across relationship partners, suggesting that some people tend to be generally happy (or unhappy) across relationships, and this is due, in part, to stable individual differences in personality. Discussion focuses on the broader implications of the findings, in particular the need for relationship researchers to consider the importance of personality for why relationships thrive or fail and the need for personality researchers to consider the impact of relationship experiences on intraindividual personality development. [ABSTRACT FROM AUTHOR]

Background: This paper describes the circumstances of contemporary young mothers and their children from a nationally representative sample, and compares them to the circumstances of mothers who delayed childbearing beyond age 20. Methods: The participants are members of the Environmental Risk (E-risk) Longitudinal Twin Study, which follows an epidemiological sample of 1,116 women who became mothers in England and Wales in 1994-95, and their children, and contains an over-sample of young mothers. Home visits were conducted when the children were aged 5 years. Data were collected from mothers via interviews, from children via experimental tasks and observations, and from teachers via postal questionnaires. Results: Young mothers encountered more socio-economic deprivation, had significantly less human and social capital, and experienced more mental health difficulties. Their partners were less reliable and supportive, both economically and emotionally, and were more antisocial and abusive. The children of young mothers showed reduced educational attainment, were rated by multiple informants as having more emotional and behavioural problems, were at increased risk of maltreatment or harm, and showed higher rates of illnesses, accidents, and injuries. Conclusions: Young mothers today face difficulties known to have long-lasting effects for women and their children. Preventions that target young mothers may reduce harm to the physical health, mental health, and social status of future generations. [ABSTRACT FROM AUTHOR]

Aim To assess the possible effects of tobacco and cannabis smoking on lung function in young adults between the ages of 18 and 26. Setting and participants A group of over 900 young adults derived from a birth cohort of 1037 subjects born in Dunedin, New Zealand in 1972/73 were studied at age 18, 21 and 26 years. Measurements Cannabis and tobacco smoking were documented at each age using a standardized interview. Lung function, as measured by the forced expiratory volume in one second/vital capacity (FEV[sub 1]/VC) ratio, was obtained by simple spirometry. A fixed effects regression model was used to analyse the data to take account of confounding factors. Findings When the sample was stratified for cumulative use, there was evidence of a linear relationship between cannabis use and FEV[sub 1]/VC (P < 0.05). In the absence of adjusting for other variables, increasing cannabis use over time was associated with a decline in FEV[sub 1]/VC with time: the mean FEV[sub 1]/VC among subjects using cannabis on 900 or more occasions was 7.2%, 2.6% and 5.0% less than non-users at ages 18, 21 and 26, respectively. After controlling for potential confounding factors (age, tobacco smoking and weight) the negative effect of cumulative cannabis use on mean FEV[sub 1]/VC was only marginally significant (P < 0.09). Age (P < 0.001), cigarette smoking (P < 0.05) and weight (P < 0.001) were all significant predictors of FEV[sub 1]/VC. Cannabis use and daily cigarette smoking acted additively to influence FEV[sub 1]/VC. Conclusions Longitudinal observations over 8 years in young adults revealed a dose-dependent relationship between cumulative cannabis consumption and decline in FEV[sub 1]/VC. However, when confounders were accounted for the effect was reduced and was only marginally significant, but given the limited time frame over which observations were made, the trend suggests that continued cannabis smoking has the potential to result in clinically important impairment of lung... [ABSTRACT FROM AUTHOR]