Microsatellite polymorphisms associated with human behavioural and psychological phenotypes including a gene-environment interaction.

BACKGROUND: The genetic and environmental influences on human personality and behaviour are a complex matter of ongoing debate. Accumulating evidence indicates that short tandem repeats (STRs) in regulatory regions are good candidates to explain heritability not accessed by genome-wide association studies. METHODS: We tested for associations between the genotypes of four selected repeats and 18 traits relating to personality, behaviour, cognitive ability and mental health in a well-studied longitudinal birth cohort (n = 458-589) using one way analysis of variance. The repeats were a highly conserved poly-AC microsatellite in the upstream promoter region of the T-box brain 1 (TBR1) gene and three previously studied STRs in the activating enhancer-binding protein 2-beta (AP2-ß) and androgen receptor (AR) genes. Where significance was found we used multiple regression to assess the influence of confounding factors. RESULTS: Carriers of the shorter, most common, allele of the AR gene's GGN microsatellite polymorphism had fewer anxiety-related symptoms, which was consistent with previous studies, but in our study this was not significant following Bonferroni correction. No associations with two repeats in the AP2-ß gene withstood this correction. A novel finding was that carriers of the minor allele of the TBR1 AC microsatellite were at higher risk of conduct problems in childhood at age 7-9 (p = 0.0007, which did pass Bonferroni correction). Including maternal smoking during pregnancy (MSDP) in models controlling for potentially confounding influences showed that an interaction between TBR1 genotype and MSDP was a significant predictor of conduct problems in childhood and adolescence (p < 0.001), and of self-reported criminal behaviour up to age 25 years (p ≤ 0.02). This interaction remained significant after controlling for possible confounders including maternal age at birth, socio-economic status and education, and offspring birth weight. CONCLUSIONS: The potential functional importance of the TBR1 gene's promoter microsatellite deserves further investigation. Our results suggest that it participates in a gene-environment interaction with MDSP and antisocial behaviour. However, previous evidence that mothers who smoke during pregnancy carry genes for antisocial behaviour suggests that epistasis may influence the interaction.

Exposure to parental separation in childhood and later parenting quality as an adult: evidence from a 30-year longitudinal study.

BACKGROUND: Previous research has documented that exposure to parental separation/divorce during childhood can be associated with long-term consequences into adulthood. This study sought to extend this literature by examining associations between childhood exposure to parental separation/divorce and later parenting behavior as an adult in a New Zealand birth cohort. METHODS: Data were drawn from the Christchurch Health and Development Study (CHDS), a longitudinal study of a birth cohort of 1,265 children born in 1977 in Christchurch, New Zealand. Information about exposure to parental separation and divorce was gathered annually from birth to 15 years. At the 30-year follow-up, all cohort members who had become parents (biological or nonbiological) were assessed on several parenting dimensions (sensitivity, warmth, overreactivity, inconsistency, quality of child management, and physical punishment). RESULTS: The analyses showed that exposure to more frequent parental separation in childhood and adolescence was associated with lower levels of parental sensitivity and warmth, greater overreactivity, and an increased use of physical punishment as a parent, after controlling for a wide range of family socioeconomic and psychosocial factors, and individual child characteristics. CONCLUSIONS: The findings suggest that as exposure to parental separation increases, so does the likelihood of experiencing multiple developmental challenges in childhood and adolescence. As an adult, these life-course experiences can have small but significant associations with the quality of parenting behavior.

Stratification by smoking status reveals an association of CHRNA5-A3-B4 genotype with body mass index in never smokers.

We previously used a single nucleotide polymorphism (SNP) in the CHRNA5-A3-B4 gene cluster associated with heaviness of smoking within smokers to confirm the causal effect of smoking in reducing body mass index (BMI) in a Mendelian randomisation analysis. While seeking to extend these findings in a larger sample we found that this SNP is associated with 0.74% lower body mass index (BMI) per minor allele in current smokers (95% CI -0.97 to -0.51, P = 2.00 × 10(-10)), but also unexpectedly found that it was associated with 0.35% higher BMI in never smokers (95% CI +0.18 to +0.52, P = 6.38 × 10(-5)). An interaction test confirmed that these estimates differed from each other (P = 4.95 × 10(-13)). This difference in effects suggests the variant influences BMI both via pathways unrelated to smoking, and via the weight-reducing effects of smoking. It would therefore be essentially undetectable in an unstratified genome-wide association study of BMI, given the opposite association with BMI in never and current smokers. This demonstrates that novel associations may be obscured by hidden population sub-structure. Stratification on well-characterized environmental factors known to impact on health outcomes may therefore reveal novel genetic associations.

Accuracy of Self-report as a Method of Screening for Lifetime Occurrence of Traumatic Brain Injury Events that Resulted in Hospitalization.

BACKGROUND: Traumatic brain injury (TBI) occurs frequently during child and early adulthood, and is associated with negative outcomes including increased risk of drug abuse, mental health disorders and criminal offending. Identification of previous TBI for at-risk populations in clinical settings often relies on self-report, despite little information regarding self-report accuracy. This study examines the accuracy of adult self-report of hospitalized TBI events and the factors that enhance recall. METHODS: The Christchurch Health and Development Study is a birth cohort of 1265 children born in Christchurch, New Zealand, in 1977. A history of TBI events was prospectively gathered at each follow-up (yearly intervals 0-16, 18, 21, 25 years) using parental/self-report, verified using hospital records. RESULTS: At 25 years, 1003 cohort members were available, with 59/101 of all hospitalized TBI events being recalled. Recall varied depending on the age at injury and injury severity, with 10/11 of moderate/severe TBI being recalled. Logistic regression analysis indicated that a model using recorded loss of consciousness, age at injury, and injury severity, could accurately classify whether or not TBI would be reported in over 74% of cases. CONCLUSIONS: This research demonstrates that, even when individuals are carefully cued, many instances of TBI will not recalled in adulthood despite the injury having required a period of hospitalization. Therefore, screening for TBI may require a combination of self-report and review of hospital files to ensure that all cases are identified. (JINS, 2016, 22, 717-723).

Adiposity and psychosocial outcomes at ages 30 and 35.

PURPOSE: To examine associations between adiposity and adult psychosocial outcomes (depressive symptoms, life satisfaction, self-esteem, household income, personal income, savings/investments) in a New Zealand birth cohort, by gender. Adiposity was assessed using Body Mass Index scores classified on a 3-point scale of BMI: <25.0, overweight (25.0-29.9) or obese (≥30). METHODS: Data were gathered via face-to-face and telephone interviews for the Christchurch Health and Development Study (CHDS), comprising a birth cohort of 1265 children born in Christchurch, New Zealand, in 1977. BMI and psychosocial outcome information was collected in 2007 (30 years; n = 977) and in 2012 (35 years; n = 923). RESULTS: Population-averaged regression modeling showed evidence of statistically significant (p < 0.05) associations between increasing adiposity and adverse psychosocial outcomes for females, but not for males. After adjustment for child and family background covariates the strength of the associations for females was reduced; with four associations (depressive symptoms, life satisfaction, equivalized household income and savings/investments) remaining statistically significant (p < 0.05). In contrast, for males there was a significant (p = 0.008) positive association between adiposity and higher personal net weekly income after covariate adjustment. CONCLUSIONS: The findings suggest evidence of gender differences in the associations between adiposity and psychosocial outcomes. For females, there were small but pervasive tendencies for increasing adiposity to be related to more adverse mental health, psychological well-being and economic outcomes; whereas for males adiposity was either unrelated to these outcomes, or in the case of personal income, associated with greater economic advantage. The implications of these findings are discussed.

DUF1220 copy number is linearly associated with increased cognitive function as measured by total IQ and mathematical aptitude scores.

DUF1220 protein domains exhibit the greatest human lineage-specific copy number expansion of any protein-coding sequence in the genome, and variation in DUF1220 copy number has been linked to both brain size in humans and brain evolution among primates. Given these findings, we examined associations between DUF1220 subtypes CON1 and CON2 and cognitive aptitude. We identified a linear association between CON2 copy number and cognitive function in two independent populations of European descent. In North American males, an increase in CON2 copy number corresponded with an increase in WISC IQ (R (2) = 0.13, p = 0.02), which may be driven by males aged 6-11 (R (2) = 0.42, p = 0.003). We utilized ddPCR in a subset as a confirmatory measurement. This group had 26-33 copies of CON2 with a mean of 29, and each copy increase of CON2 was associated with a 3.3-point increase in WISC IQ (R (2) = 0.22, p = 0.045). In individuals from New Zealand, an increase in CON2 copy number was associated with an increase in math aptitude ability (R (2) = 0.10 p = 0.018). These were not confounded by brain size. To our knowledge, this is the first study to report a replicated association between copy number of a gene coding sequence and cognitive aptitude. Remarkably, dosage variations involving DUF1220 sequences have now been linked to human brain expansion, autism severity and cognitive aptitude, suggesting that such processes may be genetically and mechanistically inter-related. The findings presented here warrant expanded investigations in larger, well-characterized cohorts.

Genome-Wide Meta-Analysis of Longitudinal Alcohol Consumption Across Youth and Early Adulthood.

The public health burden of alcohol is unevenly distributed across the life course, with levels of use, abuse, and dependence increasing across adolescence and peaking in early adulthood. Here, we leverage this temporal patterning to search for common genetic variants predicting developmental trajectories of alcohol consumption. Comparable psychiatric evaluations measuring alcohol consumption were collected in three longitudinal community samples (N=2,126, obs=12,166). Consumption-repeated measurements spanning adolescence and early adulthood were analyzed using linear mixed models, estimating individual consumption trajectories, which were then tested for association with Illumina 660W-Quad genotype data (866,099 SNPs after imputation and QC). Association results were combined across samples using standard meta-analysis methods. Four meta-analysis associations satisfied our pre-determined genome-wide significance criterion (FDR<0.1) and six others met our 'suggestive' criterion (FDR<0.2). Genome-wide significant associations were highly biological plausible, including associations within GABA transporter 1, SLC6A1 (solute carrier family 6, member 1), and exonic hits in LOC100129340 (mitofusin-1-like). Pathway analyses elaborated single marker results, indicating significant enriched associations to intuitive biological mechanisms, including neurotransmission, xenobiotic pharmacodynamics, and nuclear hormone receptors (NHR). These findings underscore the value of combining longitudinal behavioral data and genome-wide genotype information in order to study developmental patterns and improve statistical power in genomic studies.

Perceptions of distress and positive consequences following exposure to a major disaster amongst a well-studied cohort.

OBJECTIVES: Research on the impact of natural disasters on health and well-being faces several methodological challenges, including: sampling issues; exposure assessment; and outcome measurement. The present study used a comprehensive measure of disaster exposure to assess relationships between exposure to the Canterbury (New Zealand) Earthquakes of 2010-2011 and both: (a) self-reported distress and (b) positive outcomes; and also investigated gender differences in reports. METHODS: Data were gathered from the Christchurch Health and Development Study, a 35-year longitudinal study. The study examined data from 495 individuals exposed to the Canterbury Earthquakes for who complete data on exposure and reactions to the earthquakes at age 35 were available. RESULTS: Participants with higher levels of exposure to the earthquakes reported significantly (p<0.0001) higher levels of distress due to fear, death and injury, and disruption caused by the earthquakes. Higher levels of exposure to the earthquakes were also associated with significantly (p<0.0001) higher levels of reporting positive consequences following the earthquakes. Women reported significantly (p<0.0001) greater distress than men and significantly (p<0.001) greater positive consequences. CONCLUSIONS: Higher levels of exposure to disaster were associated with higher levels of distress, but also with higher levels of self-reported positive outcomes, with females reporting higher levels of both positive and negative outcomes. The findings highlight the need for comprehensive assessment of disaster exposure, to consider gender and other group differences in reactions to disaster exposure, and for studies of disasters to examine both positive and negative consequences.

Leaving school without qualifications and mental health problems to age 30.

PURPOSE: To examine the associations between leaving school without qualifications and subsequent mental health to age 30, using data gathered over the course of a 30-year longitudinal study. METHODS: Data were gathered over the course of a 30-year study (Christchurch Health and Development Study) of a birth cohort of 1265 children, born in Christchurch in 1977. This cohort has been studied on 22 occasions from birth to age 30. As part of this study, information was gathered on: (a) school leaving qualifications, (b) mental health problems from 18 to 30; and (c) prospectively assessed childhood and adolescent factors including: child and family background; family violence and child abuse; and adolescent mental health problems. RESULTS: Leaving school without qualifications was associated with increased risks of subsequent: major depression (OR = 1.37 at 95 % CI 1.05-1.78, p = 0.019); anxiety disorder (OR = 1.99 at 95 % CI 1.55-2.57, p < 0.001); suicidal ideation/attempt (OR = 1.60 at 95 % CI 1.15-2.36, p = 0.005); alcohol abuse/dependence (OR = 1.54 at 95 % CI 1.20-1.98, p < 0.001); and illicit substance abuse/dependence (OR = 2.97 at 95 % CI 2.16-4.07, p < 0.001). Adjustment for the covariate factors above (family social background; family violence; child abuse and adolescent mental health problems) reduced these associations substantially and to the point of statistical non-significance. CONCLUSIONS: The findings of this study suggest that there was no direct causal association between leaving school without qualifications and subsequent mental health problems. Associations were explained by the linkages between leaving school without qualifications and: child and family social background; and mental health around the point of school leaving.

Psychosocial sequelae of cannabis use and implications for policy: findings from the Christchurch Health and Development Study.

BACKGROUND: The Christchurch Health and Development Study is a longitudinal study of a birth cohort of 1265 children who were born in Christchurch, New Zealand, in 1977. This cohort has now been studied from birth to the age of 35. SCOPE OF THIS REVIEW: This article examines a series of findings from the CHDS that address a range of issues relating to the use of cannabis amongst the cohort. These issues include: (a) patterns of cannabis use and cannabis dependence; (b) linkages between cannabis use and adverse educational and economic outcomes; (c) cannabis and other illicit drug use; (d) cannabis and psychotic symptoms; (e) other CHDS findings related to cannabis; and (f) the consequences of cannabis use for adults using cannabis regularly. FINDINGS: In general, the findings of the CHDS suggest that individuals who use cannabis regularly, or who begin using cannabis at earlier ages, are at increased risk of a range of adverse outcomes, including: lower levels of educational attainment; welfare dependence and unemployment; using other, more dangerous illicit drugs; and psychotic symptomatology. It should also be noted, however, that there is a substantial proportion of regular adult users who do not experience harmful consequences as a result of cannabis use. CONCLUSIONS: Collectively, these findings suggest that cannabis policy needs to be further developed and evaluated in order to find the best way to regulate a widely-used, and increasingly legal substance.

Parental separation/divorce in childhood and partnership outcomes at age 30.

BACKGROUND: Previous research has found that children exposed to separation/divorce may also experience relationship problems in adulthood. The aim of this investigation was to examine this issue in a birth cohort of over 900 New Zealand children studied to age 30. METHODS: Data were gathered over the course of the Christchurch Health and Development Study (CHDS). The CHDS is a 30 year longitudinal study of a birth cohort of 1265 children born in Christchurch (NZ) in 1977. The data collected included the following: (a) timing and number of parental separations and divorces from birth to 15 years; (b) partnership outcomes (16-30 years) of the number of cohabiting/marriage partnerships; positive partner relations; negative partner relations; partner adjustment/conduct problems; and interpartner violence victimization and perpetration; and (c) potential covariate factors. RESULTS: Study findings showed the presence of significant associations between childhood parental separations/divorces and number of cohabiting/marriage partnerships (16-30 years) (p < .001), negative partner relations (p = .021), extent of partner adjustment/conduct problems (p < .001), and perpetration of interpartner violence (p = .018). Childhood parental separation/divorce explained less than 2.5% of the variance in partnership outcomes. These associations were explained statistically by a series of covariate factors associated with childhood parental separation/divorce including parental history of illicit drug use, childhood sexual abuse, childhood conduct problems (7-9 years), interparental conflict and violence, childhood physical punishment/maltreatment, family socio-economic status at the child's birth, and parental history of criminality. Tests of gender interaction showed that the effect of childhood parental separations/divorces may be the same for males and females. Analysis of the number of childhood parental separations/divorces experienced into three age groups (birth to 5, 5-10 years and 10-15 years) yielded similar results. CONCLUSIONS: These findings suggest that the general associations between childhood parental separation/divorce and partner relationships in adulthood reflect the consequences of various contextual factors that are associated with childhood parental separation.

Breast feeding, infant growth, and body mass index at 30 and 35 years.

BACKGROUND: This study examined the associations between duration of breast feeding, early infant growth, and body mass index (BMI) at 30 and 35 years, in a birth cohort studied to age 35. METHODS: Data were gathered on duration of exclusive and non-exclusive breast feeding (months), early growth (kg; 0-9 months), and BMI at ages 30 and 35 from the Christchurch Health and Development Study. The Christchurch Health and Development Study is a study of a birth cohort of 1265 children, born in Christchurch in 1977. RESULTS: Population-averaged generalised estimating regression models showed statistically significant associations between: duration of breast feeding and mean BMI; and early growth and mean BMI. After adjustment for perinatal, family, and social background factors, statistically significant associations were found between: longer duration of breast feeding and lower adult BMI (B = -0.424 [95% confidence interval (CI) -0.708, -0.140]); and increasing early growth and higher adult BMI (B = 0.393 [95% CI 0.080, 0.707]). When breast feeding and infant growth were entered into the regression model and adjusted for covariates, breast feeding was no longer statistically significantly associated with BMI (B = -0.250 [95% CI -0.553, 0.054]), while early growth remained statistically significantly associated with BMI (B = 0.355 [95% CI 0.039, 0.671]). A test for mediation showed that the association between breast feeding and BMI was mediated by early growth (P = 0.01). CONCLUSIONS: The association between longer duration of breast feeding and later lower BMI scores in adulthood was mediated by lower early growth. Breast feeding may be included as one component of multicompartment programmes targeted at early growth and later obesity.

Childhood socio-economic status and ethnic disparities in psychosocial outcomes in New Zealand.

OBJECTIVE: The present study examined the extent to which childhood socio-economic status (SES) could account for differences in adult psychosocial outcomes between Maori and non-Maori individuals in a birth cohort of more than 1000 individuals studied to age 30. METHODS: Data were gathered on three measures of childhood SES (family SES, family living standards, family income) and adult psychosocial outcomes including mental health, substance use, criminal offending, and education/welfare dependence outcomes, as part of a longitudinal study of a New Zealand birth cohort (the Christchurch Health and Development Study). RESULTS: Those reporting Maori ethnicity had significantly (p < 0.0001) poorer scores on the three measures of childhood SES, with estimates of Cohen's d indicating a moderate effect size. Maori cohort members also had significantly (p < 0.05) greater rates of adverse psychosocial outcomes in adulthood. Controlling for childhood SES reduced the magnitude of the ethnic differences in psychosocial outcomes, but did not fully explain the differences between Maori and non-Maori. Adjustment for childhood SES had the strongest effect on education/welfare dependence, but weaker effects on mental health, substance use, and criminal offending. CONCLUSIONS: Improvements in SES among Maori in New Zealand may, to some extent, ameliorate the long standing disparities in psychosocial well-being between Maori and non-Maori. However, efforts to improve Maori well-being will require an approach that moves beyond a sole focus on rectifying socio-economic disadvantage.

Unemployment and psychosocial outcomes to age 30: A fixed-effects regression analysis.

OBJECTIVE: We aimed to examine the associations between exposure to unemployment and psychosocial outcomes over the period from 16 to 30 years, using data from a well-studied birth cohort. METHODS: Data were collected over the course of the Christchurch Health and Development Study, a longitudinal study of a birth cohort of 1265 children, born in Christchurch in 1977, who have been studied to age 30. Assessments of unemployment and psychosocial outcomes (mental health, substance abuse/dependence, criminal offending, adverse life events and life satisfaction) were obtained at ages 18, 21, 25 and 30. RESULTS: Prior to adjustment, an increasing duration of unemployment was associated with significant increases in the risk of all psychosocial outcomes. These associations were adjusted for confounding using conditional, fixed-effects regression techniques. The analyses showed significant (p < 0.05) or marginally significant (p < 0.10) associations between the duration of unemployment and major depression (p = 0.05), alcohol abuse/dependence (p = 0.043), illicit substance abuse/dependence (p = 0.017), property/violent offending (p < 0.001), arrests/convictions (p = 0.052), serious financial problems (p = 0.007) and life satisfaction (p = 0.092). To test for reverse causality, the fixed-effects regression models were extended to include lagged, time-dynamic variables representing the respondent's psychosocial burden prior to the experience of unemployment. The findings suggested that the association between unemployment and psychosocial outcomes was likely to involve a causal process in which unemployment led to increased risks of adverse psychosocial outcomes. Effect sizes were estimated using attributable risk; exposure to unemployment accounted for between 4.2 and 14.0% (median 10.8%) of the risk of experiencing the significant psychosocial outcomes. CONCLUSIONS: The findings of this study suggest that exposure to unemployment had small but pervasive effects on psychosocial adjustment in adolescence and young adulthood.

Protocol for a collaborative meta-analysis of 5-HTTLPR, stress, and depression.

BACKGROUND: Debate is ongoing about what role, if any, variation in the serotonin transporter linked polymorphic region (5-HTTLPR) plays in depression. Some studies report an interaction between 5-HTTLPR variation and stressful life events affecting the risk for depression, others report a main effect of 5-HTTLPR variation on depression, while others find no evidence for either a main or interaction effect. Meta-analyses of multiple studies have also reached differing conclusions. METHODS/DESIGN: To improve understanding of the combined roles of 5-HTTLPR variation and stress in the development of depression, we are conducting a meta-analysis of multiple independent datasets. This coordinated approach utilizes new analyses performed with centrally-developed, standardized scripts. This publication documents the protocol for this collaborative, consortium-based meta-analysis of 5-HTTLPR variation, stress, and depression. STUDY ELIGIBILITY CRITERIA: Our goal is to invite all datasets, published or unpublished, with 5-HTTLPR genotype and assessments of stress and depression for at least 300 subjects. This inclusive approach is to minimize potential impact from publication bias. DATA SOURCES: This project currently includes investigators from 35 independent groups, providing data on at least N = 33,761 participants.The analytic plan was determined prior to starting data analysis. Analyses of individual study datasets will be performed by the investigators who collected the data using centrally-developed standardized analysis scripts to ensure a consistent analytical approach across sites. The consortium as a group will review and interpret the meta-analysis results. DISCUSSION: Variation in 5-HTTLPR is hypothesized to moderate the response to stress on depression. To test specific hypotheses about the role of 5-HTTLPR variation on depression, we will perform coordinated meta-analyses of de novo results obtained from all available data, using variables and analyses determined a priori. Primary analyses, based on the original 2003 report by Caspi and colleagues of a GxE interaction will be supplemented by secondary analyses to help interpret and clarify issues ranging from the mechanism of effect to heterogeneity among the contributing studies. Publication of this protocol serves to protect this project from biased reporting and to improve the ability of readers to interpret the results of this specific meta-analysis upon its completion.

Does abortion reduce the mental health risks of unwanted or unintended pregnancy? A re-appraisal of the evidence.

OBJECTIVE: There have been debates about the linkages between abortion and mental health. Few reviews have considered the extent to which abortion has therapeutic benefits that mitigate the mental health risks of abortion. The aim of this review was to conduct a re-appraisal of the evidence to examine the research hypothesis that abortion reduces rates of mental health problems in women having unwanted or unintended pregnancy. METHODS: Analysis of recent reviews (Coleman, 2011; National Collaborating Centre for Mental Health, 2011) identified eight publications reporting 14 adjusted odds ratios (AORs) spanning five outcome domains: anxiety; depression; alcohol misuse; illicit drug use/misuse; and suicidal behaviour. For each outcome, pooled AORs were estimated using a random-effects model. RESULTS: There was consistent evidence to show that abortion was not associated with a reduction in rates of mental health problems (p>0.75). Abortion was associated with small to moderate increases in risks of anxiety (AOR 1.28, 95% CI 0.97-1.70; p<0.08), alcohol misuse (AOR 2.34, 95% CI 1.05-5.21; p<0.05), illicit drug use/misuse (AOR 3.91, 95% CI 1.13-13.55; p<0.05), and suicidal behaviour (AOR 1.69, 95% CI 1.12-2.54; p<0.01). CONCLUSIONS: There is no available evidence to suggest that abortion has therapeutic effects in reducing the mental health risks of unwanted or unintended pregnancy. There is suggestive evidence that abortion may be associated with small to moderate increases in risks of some mental health problems.

The intergenerational transmission of conduct problems.

PURPOSE: Drawing on prospective longitudinal data, this paper examines the intergenerational transmission of childhood conduct problems in a sample of 209 parents and their 331 biological offspring studied as part of the Christchurch Health and Developmental Study. The aims were to estimate the association between parental and offspring conduct problems and to examine the extent to which this association could be explained by (a) confounding social/family factors from the parent's childhood and (b) intervening factors reflecting parental behaviours and family functioning. METHODS: The same item set was used to assess childhood conduct problems in parents and offspring. Two approaches to data analysis (generalised estimating equation regression methods and latent variable structural equation modelling) were used to examine possible explanations of the intergenerational continuity in behaviour. RESULTS: Regression analysis suggested that there was moderate intergenerational continuity (r = 0.23, p < 0.001) between parental and offspring conduct problems. This continuity was not explained by confounding factors but was partially mediated by parenting behaviours, particularly parental over-reactivity. Latent variable modelling designed to take account of non-observed common genetic and environmental factors underlying the continuities in problem behaviours across generations also suggested that parenting behaviour played a role in mediating the intergenerational transmission of conduct problems. CONCLUSIONS: There is clear evidence of intergenerational continuity in conduct problems. In part this association reflects a causal chain process in which parental conduct problems are associated (directly or indirectly) with impaired parenting behaviours that in turn influence risks of conduct problems in offspring.

The quality of parent/child relationships in adolescence is associated with poor adult psychosocial adjustment.

This study used data gathered over the course of a New Zealand longitudinal study (N = 924) to examine the relationships between measures of parental bonding and attachment in adolescence (age 15-16) and later personal adjustment (major depression; anxiety disorder; suicidal behaviour; illicit drug abuse/dependence; crime) assessed up to the age of 30. Key findings included: 1) There were significant (p < 0.05) and pervasive associations between all measures of attachment and bonding and later outcomes. 2) Structural equation modelling showed that all measures of bonding and attachment loaded on a common factor reflecting the quality of parent/child relationships in adolescence. 3) After adjustment for covariates there were modest relationships (ß = 0.16-0.17) between the quality of parent/child relationships in adolescence factor and later adjustment. The study findings suggest that the quality of parent/child relationships in adolescence is modestly related to later psychosocial functioning in adulthood.

Moderating role of the MAOA genotype in antisocial behaviour.

BACKGROUND: Recent studies have examined gene×environment (G×E) interactions involving the monoamine oxidase A (MAOA) gene in moderating the associations between exposure to adversity and antisocial behaviour. The present study examined a novel method for assessing interactions between a single gene and multiple risk factors related to environmental and personal adversity. AIMS: To test the hypothesis that the presence of the low-activity MAOA genotype was associated with an increased response to a series of risk factors. METHOD: Participants were 399 males from the Christchurch Health and Development Study who had complete data on: (a) MAOA promoter region variable number tandem repeat genotype; (b) antisocial behaviour (criminal offending) to age 30 and convictions to age 21; and (c) maternal smoking during pregnancy, IQ, childhood maltreatment and school failure. RESULTS: Poisson regression models were fitted to three antisocial behaviour outcomes (property/violent offending ages 15-30; and convictions ages 17-21), using measures of exposure to adverse childhood circumstances. The analyses revealed consistent evidence of G x E interactions, such that those with the low-activity MAOA variant who were exposed to adversity in childhood were significantly more likely to report offending in late adolescence and early adulthood. CONCLUSIONS: The present findings add to the evidence suggesting that there is a stable G x E interaction involving MAOA, a range of adverse environmental and personal factors, and antisocial behaviour across the life course. These analyses also demonstrate the utility of using multiple environmental/personal exposures to test G×E interactions.

The links between ethnicity, cultural identity and alcohol use, abuse and dependence in a New Zealand birth cohort.

AIMS: To examine the role of ethnicity and cultural identity in alcohol use and misuse in a birth cohort of over 1000 young people. METHODS: Data on ethnicity, cultural identification, alcohol use, alcohol abuse/dependence (AAD), socio-economic factors and childhood adversity were gathered as part of a longitudinal study of a New Zealand birth cohort (the Christchurch Health and Development Study). RESULTS: Those reporting Maori ethnicity had rates of alcohol use and AAD that were 1.47-1.63 times higher than the rates found in the non-Maori people. However, there was little evidence to suggest that rates of alcohol use and AAD differed according to Maori cultural identity. Generalized estimating equation regression analyses adjusting for socio-economic disadvantage and childhood adversity slightly reduced the magnitude of these associations, but they remained statistically significant [AAD: odds ratio = 1.52; 95% confidence interval (CI): 1.11-2.10; consumption: incidence rate ratio = 1.31; 95% CI: 1.13-1.52]. CONCLUSION: (a) Maori ethnicity was found to be associated with modestly increased risks of alcohol use and AAD (b) the higher rates of alcohol use and AAD among the Maori members of the cohort could not be explained by a combination of socio-economic factors and greater exposure to environmental factors known to influence the risk of alcohol use and misuse.