Exposure to Community Violence as a Mechanism Linking Neighborhood Socioeconomic Disadvantage and Neural Responses to Reward

A growing literature links socioeconomic disadvantage and adversity to brain function, including disruptions in reward processing. Less research has examined exposure to community violence as a specific adversity related to differences in reward-related brain activation, despite the prevalence of community violence exposure for those living in disadvantaged contexts. The current study tested whether exposure to community violence was associated with reward-related ventral striatum activation after accounting for familial factors associated with differences in reward-related activation (e.g., parenting, family income). Moreover, we tested whether exposure to community violence is a mechanism linking socioeconomic disadvantage to reward-related activation in the ventral striatum. We utilized data from 444 adolescent twins sampled from birth records and residing in neighborhoods with above-average levels of poverty. Exposure to community violence was associated with greater reward-related ventral striatum activation, and the association remained after accounting for family-level markers of disadvantage. We identified an indirect pathway in which socioeconomic disadvantage predicted greater reward-related activation via greater exposure to community violence, over and above family-level adversity. These findings highlight the unique impact of community violence exposure on reward processing and provide a mechanism through which socioeconomic disadvantage may shape brain function.

Midlife diseases of despair and cardiometabolic risk: testing shared origins in adolescent psychopathology

BACKGROUND

Rising midlife mortality in the United States is largely attributable to 'deaths of despair' (deaths from suicide, drug poisonings, and alcohol-related diseases) and deaths from cardiometabolic conditions. Although despair- and cardiometabolic-related mortality are increasing concurrently, it is unclear whether they share common developmental origins. We tested adolescent psychopathology as a potential common origin of midlife diseases of despair and cardiometabolic risk.

METHODS

Participants (N = 4578) were from the National Longitudinal Study of Adolescent to Adult Health, a nationally representative cohort followed from adolescence to early midlife. Adolescent psychopathology included depression, anxiety, eating disorders, PTSD, conduct disorder, and ADHD at ages 11-18. Diseases of despair (suicidality, substance misuse, pain, and sleep problems) and cardiometabolic risk (hypertension, hyperlipidemia, high-risk waist circumference, diabetes, and cardiovascular conditions) were multi-modally measured at ages 33-43.

RESULTS

At midlife, adolescents who experienced psychopathology exhibited more indicators of despair-related diseases and cardiometabolic risk (IRRs = 1.67 [1.46-1.87] and 1.13 [1.04-1.21], respectively), even after accounting for demographics, adolescent SES, and adolescent cognitive ability. Associations were evident for internalizing and externalizing conditions, and in a dose-response fashion. In mediation analyses, low education explained little of these associations, but early-adult substance use explained 21.5% of psychopathology's association with despair-related diseases. Midlife despair-related diseases and cardiometabolic risk co-occurred within individuals (IRR = 1.12 [1.08-1.16]). Adolescent psychopathology accounted for 8.3% of this co-occurrence, and 16.7% together with adolescent SES and cognitive ability.

CONCLUSIONS

Adolescent psychopathology precedes both diseases of despair and cardiometabolic risk. Prevention and treatment of psychopathology may mitigate multiple causes of poor midlife health, reducing premature mortality.

Dementia, dementia's risk factors and premorbid brain structure are concentrated in disadvantaged areas: National register and birth-cohort geographic analyses

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.

Peer connectedness and substance use in adolescence: A systematic review and meta-analysis

OBJECTIVE

Adolescents' relationships with their peers play a pivotal role in their substance-use behaviors. As such, decades of research have examined how substance use relates to adolescents' overall levels of closeness to their peers, here termed peer connectedness, with mixed results. This report sought to determine how the operationalizations of peer connectedness and substance use affect the nature of the relationship between them.

METHOD

We used a systematic review strategy to find a comprehensive set of studies investigating the relationship between peer connectedness and substance use. Three-level meta-analytic regression was used to empirically test whether the operationalization of these variables moderates effect sizes across studies.

RESULTS

We found 147 studies, of which 128 were analyzed using multilevel meta-analytic regression models. Operationalizations of peer connectedness varied widely, encompassing sociometric and self-report measures. Of these measures, sociometric indices specifically pertaining to popularity were most strongly predictive of substance use. Less consistent relationships were observed between substance use and sociometric measures of friendship, as well as with self-report measures.

CONCLUSIONS

Being perceived as popular by one's peers is positively related to substance use among adolescents. This relationship is stronger and more consistent than those between substance use and other peer-connectedness variables, underscoring the necessity of operationalizing these constructs specifically and clearly. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Suicides, drug poisonings, and alcohol-related deaths cluster with health and social disadvantage in 4.1 million citizens from two nations

BACKGROUND

Deaths from suicides, drug poisonings, and alcohol-related diseases ('deaths of despair') are well-documented among working-age Americans, and have been hypothesized to be largely specific to the U.S. However, support for this assertion-and associated policies to reduce premature mortality-requires tests concerning these deaths in other industrialized countries, with different institutional contexts. We tested whether the concentration and accumulation of health and social disadvantage forecasts deaths of despair, in New Zealand and Denmark.

METHODS

We used nationwide administrative data. Our observation period was 10 years (NZ = July 2006-June 2016, Denmark = January 2007-December 2016). We identified all NZ-born and Danish-born individuals aged 25-64 in the last observation year (NZ = 1 555 902, Denmark = 2 541 758). We ascertained measures of disadvantage (public-hospital stays for physical- and mental-health difficulties, social-welfare benefit-use, and criminal convictions) across the first nine years. We ascertained deaths from suicide, drugs, alcohol, and all other causes in the last year.

RESULTS

Deaths of despair clustered within a population segment that disproportionately experienced multiple disadvantages. In both countries, individuals in the top 5% of the population in multiple health- and social-service sectors were at elevated risk for deaths from suicide, drugs, and alcohol, and deaths from other causes. Associations were evident across sex and age.

CONCLUSIONS

Deaths of despair are a marker of inequalities in countries beyond the U.S. with robust social-safety nets, nationwide healthcare, and strong pharmaceutical regulations. These deaths cluster within a highly disadvantaged population segment identifiable within health- and social-service systems.

Disordered gambling in a longitudinal birth cohort: from childhood precursors to adult life outcomes

BACKGROUND

Despite its introduction into the diagnostic nomenclature over four decades ago, there remain large knowledge gaps about disordered gambling. The primary aims of the present study were to document the long-term course, childhood precursors, and adult life outcomes associated with disordered gambling.

METHODS

Participants enrolled in the population-representative Dunedin Study were prospectively followed from birth through age 45. Disordered gambling was assessed six times from age 18; composite measures of childhood social class, general intelligence, and low self-control were based on assessments obtained from birth through age 15; adult socioeconomic, financial, and legal outcomes were obtained through age 45. Lifetime disordered gambling was predicted from the three childhood precursors and the adult outcomes were predicted from lifetime disordered gambling.

RESULTS

Past-year disordered gambling usually occurred at only a single time point and recurrence was relatively uncommon. Lower childhood social class, general intelligence, and self-control significantly predicted lifetime disordered gambling in adulthood. In turn, lifetime disordered gambling in adulthood significantly predicted occupational, educational, and financial problems in adulthood (ds = 0.23-0.41). These associations were markedly reduced and sometimes rendered nonsignificant after adjusting for childhood precursors (ds = 0.04-0.32).

CONCLUSIONS

Socioeconomic, financial, and legal outcomes in adulthood are not merely consequences of disordered gambling, but also are predicted from childhood precursors. Deflecting the trajectories of young people at risk for developing disordered gambling may help to ameliorate not just the development of later disordered gambling, but also other associated adverse outcomes.

Use of Population-Level Administrative Data in Developmental Science

Population-level administrative data-data on individuals' interactions with administrative systems (e.g., health, criminal justice, and education)-have substantially advanced our understanding of life-course development. In this review, we focus on five areas where research using these data has made significant contributions to developmental science: (a) understanding small or difficult-to-study populations, (b) evaluating intergenerational and family influences, (c) enabling estimation of causal effects through natural experiments and regional comparisons, (d) identifying individuals at risk for negative developmental outcomes, and (e) assessing neighborhood and environmental influences. Further advances will be made by linking prospective surveys to administrative data to expand the range of developmental questions that can be tested; supporting efforts to establish new linked administrative data resources, including in developing countries; and conducting cross-national comparisons to test findings' generalizability. New administrative data initiatives should involve consultation with population subgroups including vulnerable groups, efforts to obtain social license, and strong ethical oversight and governance arrangements.

Longitudinal Associations of Mental Disorders With Dementia: 30-Year Analysis of 1.7 Million New Zealand Citizens

IMPORTANCE

Mental disorders are an underappreciated category of modifiable risk factors for dementia. Developing an evidence base about the link between mental disorders and dementia risk requires studies that use large, representative samples, consider the full range of psychiatric conditions, ascertain mental disorders from early life, use long follow-ups, and distinguish between Alzheimer disease and related dementias.

OBJECTIVE

To test whether mental disorders antedate dementia across 3 decades of observation.

DESIGN, SETTING, AND PARTICIPANTS

This population-based administrative register study of mental disorders and Alzheimer disease and related dementias included all individuals born in New Zealand between 1928 and 1967 who resided in the country for any time during the 30-year observation period between July 1988 and June 2018. Data were from the New Zealand Integrated Data Infrastructure, a collection of whole-of-population administrative data sources linked at the individual level. Data were analyzed from October 2020 to November 2021.

EXPOSURES

Diagnoses of mental disorders were ascertained from public-hospital records.

MAIN OUTCOMES AND MEASURES

Diagnoses of dementia were ascertained from public-hospital records, mortality records, and pharmaceutical records.

RESULTS

Of 1 711 386 included individuals, 866 301 (50.6%) were male, and individuals were aged 21 to 60 years at baseline. Relative to individuals without a mental disorder, those with a mental disorder were at increased risk of developing subsequent dementia (relative risk [RR], 4.24; 95% CI, 4.07-4.42; hazard ratio, 6.49; 95% CI, 6.25-6.73). Among individuals with dementia, those with a mental disorder developed dementia a mean of 5.60 years (95% CI, 5.31-5.90) earlier than those without a mental disorder. Associations held across sex and age and after accounting for preexisting chronic physical diseases and socioeconomic deprivation. Associations were present across different types of mental disorders and self-harm behavior (RRs ranged from 2.93 [95% CI, 2.66-3.21] for neurotic disorders to 6.20 [95% CI, 5.67-6.78] for psychotic disorders), and were evident for Alzheimer disease (RR, 2.76; 95% CI, 2.45-3.11) and all other dementias (RR, 5.85; 95% CI, 5.58-6.13).

CONCLUSIONS AND RELEVANCE

In this study, mental disorders were associated with the onset of dementia in the population. Ameliorating mental disorders in early life might also ameliorate neurodegenerative conditions and extend quality of life in old age.

Association of History of Psychopathology With Accelerated Aging at Midlife

IMPORTANCE

Individuals with mental disorders are at an elevated risk of developing chronic age-related physical diseases. However, it is not clear whether psychopathology is also associated with processes of accelerated aging that precede the onset of age-related disease.

OBJECTIVE

To test the hypothesis that a history of psychopathology is associated with indicators of accelerated aging at midlife.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was based on the Dunedin Multidisciplinary Health and Development Study, a population-representative birth cohort of 1037 individuals born between April 1, 1972, and March 31, 1973, in Dunedin, New Zealand. Members were followed up to age 45 years (until April 2019). Data were analyzed from January 6 to December 7, 2020.

EXPOSURES

Mental disorders were assessed in 6 diagnostic assessments from ages 18 to 45 years and transformed through confirmatory factor analysis into continuous measures of general psychopathology (p-factor) and dimensions of internalizing, externalizing, and thought disorders (all standardized to a mean [SD] of 100 [15]).

MAIN OUTCOMES AND MEASURES

Signs of aging (biological pace of aging; declines in sensory, motor, and cognitive functioning; and facial age) were assessed up to age 45 years using previously validated measures including biomarkers, clinical tests, and self-reports.

RESULTS

Of the original 1037 cohort participants, 997 were still alive at age 45 years, of whom 938 (94%) were assessed (474 men [50.5%]). Participants who had experienced more psychopathology exhibited a faster pace of biological aging (β, 0.27; 95% CI, 0.21-0.33; P < .01); experienced more difficulties with hearing (β, 0.18; 95% CI, 0.12-0.24; P < .01), vision (β, 0.08; 95% CI, 0.01-0.14; P < .05), balance (β, 0.20; 95% CI, 0.14-0.26; P < .01), and motor functioning (β, 0.19; 95% CI, 0.12-0.25; P < .01); experienced more cognitive difficulties (β, 0.24; 95% CI, 0.18-0.31; P < .01); and were rated as looking older (β, 0.20; 95% CI, 0.14-0.26; P < .01). Associations persisted after controlling for sex, childhood health indicators, maltreatment, and socioeconomic status and after taking into account being overweight, smoking, use of antipsychotic medication, and the presence of physical disease. Tests of diagnostic specificity revealed that associations were generalizable across externalizing, internalizing, and thought disorders.

CONCLUSIONS AND RELEVANCE

In this cohort study, a history of psychopathology was associated with accelerated aging at midlife, years before the typical onset of age-related diseases. This link is not specific to any particular disorder family but generalizes across disorders. Prevention of psychopathology and monitoring of individuals with mental disorders for signs of accelerated aging may have the potential to reduce health inequalities and extend healthy lives.

Disparities in the pace of biological aging among midlife adults of the same chronological age have implications for future frailty risk and policy

Some humans age faster than others. Variation in biological aging can be measured in midlife, but the implications of this variation are poorly understood. We tested associations between midlife biological aging and indicators of future frailty-risk in the Dunedin cohort of 1037 infants born the same year and followed to age 45. Participants' Pace of Aging was quantified by tracking declining function in 19 biomarkers indexing the cardiovascular, metabolic, renal, immune, dental, and pulmonary systems across ages 26, 32, 38, and 45 years. At age 45 in 2019, participants with faster Pace of Aging had more cognitive difficulties, signs of advanced brain aging, diminished sensory-motor functions, older appearance, and more pessimistic perceptions of aging. People who are aging more rapidly than same-age peers in midlife may prematurely need supports to sustain independence that are usually reserved for older adults. Chronological age does not adequately identify need for such supports.

Childhood self-control forecasts the pace of midlife aging and preparedness for old age

The ability to control one's own emotions, thoughts, and behaviors in early life predicts a range of positive outcomes in later life, including longevity. Does it also predict how well people age? We studied the association between self-control and midlife aging in a population-representative cohort of children followed from birth to age 45 y, the Dunedin Study. We measured children's self-control across their first decade of life using a multi-occasion/multi-informant strategy. We measured their pace of aging and aging preparedness in midlife using measures derived from biological and physiological assessments, structural brain-imaging scans, observer ratings, self-reports, informant reports, and administrative records. As adults, children with better self-control aged more slowly in their bodies and showed fewer signs of aging in their brains. By midlife, these children were also better equipped to manage a range of later-life health, financial, and social demands. Associations with children's self-control could be separated from their social class origins and intelligence, indicating that self-control might be an active ingredient in healthy aging. Children also shifted naturally in their level of self-control across adult life, suggesting the possibility that self-control may be a malleable target for intervention. Furthermore, individuals' self-control in adulthood was associated with their aging outcomes after accounting for their self-control in childhood, indicating that midlife might offer another window of opportunity to promote healthy aging.

Longitudinal Associations of Mental Disorders With Physical Diseases and Mortality Among 2.3 Million New Zealand Citizens

IMPORTANCE

Excess risk of physical disease and mortality has been observed among individuals with psychiatric conditions, suggesting that ameliorating mental disorders might also be associated with ameliorating the later onset of physical disability and early mortality. However, the temporal association between mental disorders and physical diseases remains unclear, as many studies have relied on retrospective recall, used cross-sectional designs or prospective designs with limited follow-up periods, or given inadequate consideration to preexisting physical illnesses.

OBJECTIVE

To examine whether mental disorders are associated with subsequent physical diseases and mortality across 3 decades of observation.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used data from the New Zealand Integrated Data Infrastructure, a collection of nationwide administrative data sources linked at the individual level, to identify mental disorders, physical diseases, and deaths recorded between July 1, 1988, and June 30, 2018, in the population of New Zealand. All individuals born in New Zealand between January 1, 1928, and December 31, 1978, who resided in the country at any time during the 30-year observation period were included in the analysis. Data were analyzed from July 2019 to November 2020.

EXPOSURES

Nationwide administrative records of mental disorder diagnoses made in public hospitals.

MAIN OUTCOMES AND MEASURES

Chronic physical disease diagnoses made in public hospitals, deaths, and health care use.

RESULTS

The study population comprised 2 349 897 individuals (1 191 981 men [50.7%]; age range at baseline, 10-60 years). Individuals with a mental disorder developed subsequent physical diseases at younger ages (hazard ratio [HR], 2.33; 95% CI, 2.30-2.36) and died at younger ages (HR, 3.80; 95% CI, 3.72-3.89) than those without a mental disorder. These associations remained across sex and age and after accounting for preexisting physical diseases. Associations were observed across different types of mental disorders and self-harm behavior (relative risks, 1.78-2.43; P < .001 for all comparisons). Mental disorders were associated with the onset of physical diseases and the accumulation of physical disease diagnoses (incidence rate ratio [IRR], 2.00; 95% CI, 1.98-2.03), a higher number of hospitalizations (IRR, 2.43; 95% CI, 2.39-2.48), longer hospital stays for treatment (IRR, 2.70; 95% CI, 2.62-2.79), and higher associated health care costs (b = 0.115; 95% CI, 0.112-0.118).

CONCLUSIONS AND RELEVANCE

In this study, mental disorders were likely to begin and peak in young adulthood, and they antedated physical diseases and early mortality in the population. These findings suggest that ameliorating mental disorders may have implications for improving the length and quality of life and for reducing the health care costs associated with physical diseases.

Borderline Symptoms at Age 12 Signal Risk for Poor Outcomes During the Transition to Adulthood: Findings From a Genetically Sensitive Longitudinal Cohort Study

OBJECTIVE

Borderline personality disorder in adolescence remains a controversial construct. We addressed concerns about the prognostic significance of adolescent borderline pathology by testing whether borderline symptoms at age 12 years predict functioning during the transition to adulthood, at age 18 years, in areas critical to life-course development.

METHOD

We studied members of the Environmental Risk (E-Risk) Longitudinal Twin Study, which tracks the development of a birth cohort of 2,232 British twin children. At age 12, study members' borderline symptoms were measured using mothers' reports. At age 18, study members' personality, psychopathology, functional outcomes, and experiences of victimization were measured using self-reports, coinformant reports, and official records.

RESULTS

At age 18, study members who had more borderline symptoms at age 12 were more likely to have difficult personalities, to struggle with poor mental health, to experience poor functional outcomes, and to have become victims of violence. Reports of poor outcomes were corroborated by coinformants and official records. Borderline symptoms in study members at 12 years old predicted poor outcomes over and above other behavioral and emotional problems during adolescence. Twin analyses showed that borderline symptoms in 12-year-olds were influenced by familial risk, particularly genetic risk, which accounted for associations with most poor outcomes at age 18.

CONCLUSION

Borderline symptoms in 12-year-olds signal risk for pervasive poor functioning during the transition to adulthood. This association is driven by genetic influences, suggesting that borderline symptoms and poor outcomes are manifestations of shared genetic risk.

Clustering of health, crime and social-welfare inequality in 4 million citizens from two nations

Health and social scientists have documented the hospital revolving-door problem, the concentration of crime, and long-term welfare-dependence. Have these distinct fields identified the same citizens? Using administrative databases linked to 1.7-million New Zealanders, we quantified and monetized inequality in distributions of health and social problems and tested whether they aggregate within individuals. Marked inequality was observed: Gini coefficients equaled 0.96 for criminal-convictions, 0.91 for public-hospital-nights, 0.86 for welfare-benefits, 0.74 for prescription-drug-fills, and 0.54 for injury-insurance-claims. Marked aggregation was uncovered: a small population segment accounted for a disproportionate share of use-events and costs across multiple sectors. Findings replicated in 2.3-million Danes. We then integrated the New Zealand databases with the four-decade-long Dunedin Study. The high-need/high-cost population segment experienced early-life factors that reduce workforce-readiness, including low education and poor mental-health. In midlife they reported low life-satisfaction. Investing in young people’s education/training potential could reduce health and social inequalities and enhance population wellbeing.

Using DNA From Mothers and Children to Study Parental Investment in Children's Educational Attainment

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.

Adolescent Victimization and Self-Injurious Thoughts and Behaviors: A Genetically Sensitive Cohort Study

OBJECTIVE

Victimized adolescents have an increased risk of self-injurious thoughts and behaviors. However, poor understanding of causal and non-causal mechanisms underlying this observed risk limits the development of interventions to prevent premature death in adolescents. This study tested whether pre-existing family-wide and individual vulnerabilities account for victimized adolescents' increased risk of self-injurious thoughts and behaviors.

METHOD

Participants were 2,232 British children followed from birth to 18 years of age as part of the Environmental Risk Longitudinal Twin Study. Adolescent victimization (maltreatment, neglect, sexual victimization, family violence, peer/sibling victimization, cyber victimization, and crime victimization) was assessed through interviews with participants and co-informant questionnaires at the 18-year assessment. Suicidal ideation, self-harm, and suicide attempt in adolescence were assessed through interviews with participants at 18 years.

RESULTS

Victimized adolescents had an increased risk of suicidal ideation (odds ratio [OR] 2.40, 95% CI 2.11-2.74), self-harm (OR 2.38, 95% CI 2.10-2.69), and suicide attempt (OR 3.14, 95% CI 2.54-3.88). Co-twin control and propensity score matching analyses showed that these associations were largely accounted for by pre-existing familial and individual vulnerabilities, respectively. Over and above their prior vulnerabilities, victimized adolescents still showed a modest increase in risk for suicidal ideation (OR 1.45, 95%CI 1.10-1.91) and self-harm (OR 1.50, 95% CI 1.18-1.91) but not for suicide attempt (OR 1.28, 95% CI 0.83-1.98).

CONCLUSION

Risk for self-injurious thoughts and behaviors in victimized adolescents is explained only in part by the experience of victimization. Pre-existing vulnerabilities account for a large proportion of the risk. Therefore, effective interventions to prevent premature death in victimized adolescents should not only target the experience of victimization but also address pre-existing vulnerabilities.

Adolescents Who Self-Harm and Commit Violent Crime: Testing Early-Life Predictors of Dual Harm in a Longitudinal Cohort Study

OBJECTIVE

Self-harm is associated with violent offending. However, little is known about young people who engage in "dual-harm" behavior. The authors investigated antecedents, clinical features, and life characteristics distinguishing dual-harming adolescents from those who self-harm only.

METHODS

Participants were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative U.K. cohort of 2,232 twins born in 1994 and 1995. Self-harm in adolescence was assessed through interviews at age 18. Violent offending was assessed using a computer questionnaire at age 18 and police records through age 22. Risk factors were assessed between ages 5 and 12. Adolescent mental health, victimization, personality functioning, and use of support services were measured at age 18.

RESULTS

Self-harm was associated with violent crime (odds ratio=3.50, 95% CI=2.61-4.70), even after accounting for familial risk factors. Dual harmers had been victims of violence from childhood and exhibited lower childhood self-control and lower childhood IQ than self-only harmers. Dual harmers experienced higher rates of concurrent psychotic symptoms and substance dependence. They also exhibited distinct personality styles characterized by resistance to change and by emotional and interpersonal lability. However, dual harmers were not more likely than self-only harmers to have contact with mental health services.

CONCLUSIONS

Dual harmers have self-control difficulties and are immersed in violence from a young age. A treatment- rather than punishment-oriented approach is indicated to meet these individuals' needs. Connecting self-harming adolescents with delinquency-reduction programs and transdiagnostic approaches that target self-regulation may reduce harmful behaviors. Preventing childhood maltreatment and implementing strategies to reduce victimization exposure could mitigate risk for both internalized and externalized violence.

Common genetic contributions to high-risk trauma exposure and self-injurious thoughts and behaviors

BACKGROUND

Prior research has documented shared heritable contributions to non-suicidal self-injury (NSSI) and suicidal ideation (SI) as well as NSSI and suicide attempt (SA). In addition, trauma exposure has been implicated in risk for NSSI and suicide. Genetically informative studies are needed to determine common sources of liability to all three self-injurious thoughts and behaviors, and to clarify the nature of their associations with traumatic experiences.

METHODS

Multivariate biometric modeling was conducted using data from 9526 twins [59% female, mean age = 31.7 years (range 24-42)] from two cohorts of the Australian Twin Registry, some of whom also participated in the Childhood Trauma Study and the Nicotine Addiction Genetics Project.

RESULTS

The prevalences of high-risk trauma exposure (HRT), NSSI, SI, and SA were 24.4, 5.6, 27.1, and 4.6%, respectively. All phenotypes were moderately to highly correlated. Genetic influences on self-injurious thoughts and behaviors and HRT were significant and highly correlated among men [rG = 0.59, 95% confidence interval (CI) (0.37-0.81)] and women [rG = 0.56 (0.49-0.63)]. Unique environmental influences were modestly correlated in women [rE = 0.23 (0.01-0.45)], suggesting that high-risk trauma may confer some direct risk for self-injurious thoughts and behaviors among females.

CONCLUSIONS

Individuals engaging in NSSI are at increased risk for suicide, and common heritable factors contribute to these associations. Preventing trauma exposure may help to mitigate risk for self-harm and suicide, either directly or indirectly via reductions in liability to psychopathology more broadly. In addition, targeting pre-existing vulnerability factors could significantly reduce risk for life-threatening behaviors among those who have experienced trauma.

Age of initiation and substance use progression: A multivariate latent growth analysis

An individual's age at first substance use may be associated with their risk for progression toward heavier substance involvement. To our knowledge, however, no studies within nationally representative samples have examined the relation between the timing of initiation and progression in use of multiple substances. The present study employed a sample of 9,421 participants from the National Longitudinal Study of Adolescent to Adult Health who reported on their ages of tobacco, alcohol, and cannabis initiation; frequency of tobacco, alcohol, and cannabis use; and quantity of tobacco and alcohol use across 4 waves. We fit latent growth models to examine (a) associations between the age of initiation and initial status and rate of change in substance involvement, and (b) the degree to which the timing of first substance use accounted for differences in trajectories. There were significant relations between all ages of initiation and rates of change in tobacco (βs = -0.21 to -0.31, ps < .01) and alcohol use frequency (βs = 0.14 to 0.31, ps < .001), age of cannabis initiation and rate of change in tobacco use quantity (β = 0.23, p < .01), and age of tobacco initiation and rate of change in cannabis use frequency (β = -0.14, p < .01). After adjusting for age of initiation, significant associations were observed between trajectories for tobacco and alcohol (r = .43, p < .0001) and alcohol and cannabis (r = .20, p < .05). Results highlight differences in within- and cross-substance relations between the age of initiation and rate of change in use across substances. They suggest that differences in substance use trajectories are partly accounted for by age at first use. (PsycINFO Database Record

A Novel Tobacco Use Phenotype Suggests the 15q25 and 19q13 Loci May be Differentially Associated With Cigarettes per Day and Tobacco-Related Problems

INTRODUCTION

Tobacco use is associated with variation at the 15q25 gene cluster and the cytochrome P450 (CYP) genes CYP2A6 and CYP2B6. Despite the variety of outcomes associated with these genes, few studies have adopted a data-driven approach to defining tobacco use phenotypes for genetic association analyses. We used factor analysis to generate a tobacco use measure, explored its incremental validity over a simple indicator of tobacco involvement: cigarettes per day (CPD), and tested both phenotypes in a genetic association study.

METHODS

Data were from the University of California, San Francisco Family Alcoholism Study (n = 1942) and a Native American sample (n = 255). Factor analyses employed a broad array of tobacco use variables to establish the candidate phenotype. Subsequently, we conducted tests for association with variants in the nicotinic acetylcholine receptor and CYP genes. We explored associations with CPD and our measure. We then examined whether the variants most strongly associated with our measure remained associated after controlling for CPD.

RESULTS

Analyses identified one factor that captured tobacco-related problems. Variants at 15q25 were significantly associated with CPD after multiple testing correction (rs938682: p = .00002, rs1051730: p = .0003, rs16969968: p = .0003). No significant associations were obtained with the tobacco use phenotype; however, suggestive associations were observed for variants in CYP2B6 near CYP2A6 (rs45482602: ps = .0082, .0075) and CYP4Z2P (rs10749865: ps = .0098, .0079).

CONCLUSIONS

CPD captures variation at 15q25. Although strong conclusions cannot be drawn, these finding suggest measuring additional dimensions of problems may detect genetic variation not accounted for by smoking quantity. Replication in independent samples will help further refine phenotype definition efforts.

IMPLICATIONS

Different facets of tobacco-related problems may index unique genetic risk. CPD, a simple measure of tobacco consumption, is associated with variants at the 15q25 gene cluster. Additional dimensions of tobacco problems may help to capture variation at 19q13. Results demonstrate the utility of adopting a data-driven approach to defining phenotypes for genetic association studies of tobacco involvement and provide results that can inform replication efforts.

Progression in substance use initiation: A multilevel discordant monozygotic twin design

Considerable attention has been paid to the "gateway" pattern of drug use initiation in which individuals progress from tobacco and alcohol use to cannabis and other illicit drugs. The extent to which this sequence reflects a causal impact of licit substance use on illicit substance involvement remains unclear. Clarifying the mechanisms underlying substance use initiation may help inform our understanding of risk for psychopathology, as increasing research is demonstrating associations between initiation patterns and heavier involvement. This study examined patterns of substance use initiation using a discordant twin design. Participants were 3,476 monozygotic twins (37% male) from the Australian Twin Registry who reported on their ages of tobacco, alcohol, and cannabis initiation. Multilevel proportional hazard regression models were used to (a) estimate within-twin-pair and between-twin-pair contributions to associations between the ages of onset of different drugs; and (b) examine whether the magnitude of effects differed as a function of the order of substance use initiation. Finding significant effects within twin pairs would support the hypothesis that the age of initiation of a substance causally influences the age of initiation of a subsequent substance. Finding significant effects between twin pairs would support the operation of familial influences that explain variation in the ages of initiation of multiple drugs. Within-twin-pair effects for typical patterns were modest. When initiation was atypical, however, larger within-twin-pair effects were observed and causal influences were more strongly implicated. Results support the utility of examining the timing and ordering of substance use initiation within sophisticated, genetically informative designs.

Age at first use and later substance use disorder: Shared genetic and environmental pathways for nicotine, alcohol, and cannabis

Behavioral genetic studies have provided insights into why early substance use initiation is associated with increased risk for disorder. Few genetically informative studies, however, have operationalized initiation as the timing of first use and simultaneously modeled the timing of initiation and problematic use of multiple substances. Such research can help capture the risk associated with early initiation and determine the extent to which genetic and environmental risk generalizes across substances. This study utilized a behavior genetic approach to examine the relation between the age of substance use initiation and symptoms of substance use disorder. Participants were 7,285 monozygotic and dizygotic twins (40% male, mean age at interview = 30.6 years) from the Australian Twin Registry who reported on their ages of tobacco, alcohol, and cannabis initiation and symptoms of Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM-IV) nicotine dependence, alcohol use disorder, and cannabis use disorder. Biometric modeling was conducted to (a) determine the structure of genetic and environmental influences on initiation and disorder and (b) examine their genetic and environmental overlap. The latent structure of initiation differed across men and women. The familial covariance between initiation and disorder was genetic among men and genetic and environmental among women, suggesting that the relation between first substance use and disorder is partly explained by a shared liability. After accounting for familial overlap, significant unique environmental correlations were observed, indicating that the age of initiation of multiple drugs may directly increase risk for substance-related problems. Results support the utility of conceptualizing initiation in terms of age and of adopting a multivariate approach. (PsycINFO Database Record

Investigating Progression in Substance Use Initiation Using a Discrete-Time Multiple Event Process Survival Mixture (MEPSUM) Approach

The order and timing of substance initiation has significant implications for later problematic patterns of use. Despite the need to study initiation from a multivariate framework, survival analytic methods typically cannot accommodate more than two substances in one model. The Discrete-Time Multiple Event Process Survival Mixture (MEPSUM; Dean, Bauer, & Shanahan, 2014) model represents an advance by incorporating more than two outcomes and enabling establishment of latent classes within a multivariate hazard distribution. Employing a MEPSUM approach, we evaluated patterns of tobacco, alcohol, and cannabis initiation in the National Longitudinal Study of Adolescent to Adult Health (N=18,923). We found four classes that differed in their ages and ordering of peak initiation risk. Demographics, externalizing psychopathology, and personality significantly predicted class membership. Sex differences in the association between delinquency and initiation patterns also emerged. Findings support the utility of the MEPSUM approach in elucidating developmental pathways underlying clinically relevant phenomena.

Brief report: cognitive control helps explain comorbidity between alcohol use disorder and internalizing disorders

OBJECTIVE

Alcohol use and internalizing problems frequently co-occur. Cognitive control has been implicated in their etiology, but no studies have tested whether this construct helps explain the co-occurrence of these disorders.

METHOD

A total of 1,313 undergraduate students completed assessments of cognitive control, negative emotionality, and symptoms of alcohol use disorder (AUD), depression, and generalized anxiety disorder. Structural equation models examined the extent to which overlap between AUD and internalizing problems was explained by variance specific to cognitive control and negative emotionality, as well as variance shared by both constructs.

RESULTS

Symptoms of AUD and internalizing disorders were modestly correlated (depression: r = .16; anxiety: r = .14). Variance specific to cognitive control explained a significant proportion of the correlation between AUD and both depression and generalized anxiety (depression: 19%; generalized anxiety: 18%), as did variance common to cognitive control and negative emotionality (depression: 24%; generalized anxiety: 31%). Consistent with previous work, variance specific to negative emotionality also explained a large and statistically significant proportion of the correlation between AUD and internalizing disorder symptoms. Of note, the residualized correlation for AUD symptom endorsement with both depression and generalized anxiety problems was not statistically significant after accounting for both cognitive control and negative emotionality.

CONCLUSIONS

This study provides new evidence that cognitive control may help explain the overlap between AUD and internalizing disorders while further supporting the contribution of negative emotionality to this overlap. RESULTS have implications for intervention efforts aimed at reducing comorbid alcohol use disorder and internalizing disorders, as well as general psychopathology.

Test of a potential causal influence of earlier age of gambling initiation on gambling involvement and disorder: a multilevel discordant twin design

The premise that an association between an earlier age of gambling initiation and the later development of disordered gambling is causal has not yet been empirically examined. The current study used a multilevel discordant twin design to examine the nature of this association. Participants were 3,546 same-sex twins (mean age = 37.7 years) from the Australian Twin Registry who completed a telephone interview that included an extensive assessment of gambling and related behaviors. Multilevel models were employed to estimate individual (within-twin-pair comparison) and family level (between-twin-pair comparison) effects, as well as the cross-level interaction between these effects. Family-level effects (genetic or environmental factors shared by family members) of age of gambling initiation robustly predicted later adult gambling frequency and disorder; the evidence for individual-level effects (unique factors not shared by family members, including a potentially causal effect of earlier age of gambling onset) was less robust. The results of this study suggest that the relation between earlier age of gambling initiation and later gambling involvement and disorder is primarily noncausal; efforts to delay the onset of gambling among young people may not necessarily reduce the number who later go on to develop gambling-related problems.

Causal influence of age at first drink on alcohol involvement in adulthood and its moderation by familial context

OBJECTIVE

Previous research has established a connection between early age at drinking initiation and greater alcohol involvement in adulthood, but it has not yet been established whether this is a causal effect. The current study used a multilevel discordant twin design to examine individual and contextual effects, and an interaction between these effects, of the age at drinking initiation on the frequency and quantity of drinking in adulthood.

METHOD

Participants were 4,194 same-sex twins (2,264 monozygotic, 1,924 dizygotic; 2,270 women; Mage = 29.9 years) from the Australian Twin Registry who completed a telephone interview that included assessments of the age at alcohol use initiation and past-year frequency and quantity of alcohol use. Multilevel models were estimated using data from the full sample and using data from only monozygotic twins. Individual (within-twin-pair comparison) and family contextual (between-twin-pair comparison) effects were estimated.

RESULTS

The age at first drink was related to the past-year frequency (r = -.16) and quantity of drinking (r = -.12) in young adulthood. Individual (causal) and family context effects of age at drinking onset predicted later adult drinking frequency and quantity. There was also a significant cross-level interaction between individual and family contexts for frequency but not quantity of drinking.

CONCLUSIONS

Results of this study indicate a potential causal effect of age at drinking onset on adult alcohol involvement as well as the importance of examining both individual and contextual effects in discordant twin studies.

Genetic and environmental influences on the ages of drinking and gambling initiation: evidence for distinct aetiologies and sex differences

AIMS

To investigate the genetic and environmental contributions to age at first drink (AFD) and age first gambled (AFG), assess their overlap and examine sex differences.

DESIGN

Univariate twin models were fitted to decompose the variation in AFD and AFG into additive genetic, shared environmental and unique environmental factors. Bivariate genetic models were fitted to assess the genetic and environmental contributions to the sources of covariation in AFD and AFG.

SETTING

National Australian Twin Registry.

PARTICIPANTS

A total of 4542 same-sex and opposite-sex twins aged 32-43 years, 42% male and 58% female.

MEASUREMENTS

AFD and AFG were assessed via structured psychiatric telephone interviews. Age of onset was treated as both continuous and categorical (early/late onset).

FINDINGS

AFD and AFG were modestly correlated (r = 0.18). Unique environmental influences explained a substantial proportion of the variation in both AFD (0.55, 95% confidence interval [CI] = 0.50-0.61) and AFG (0.66, 95% CI = 0.59-0.72), but these influences were uncorrelated (rE  = 0.01). Additive genetic factors explained a notable proportion of variation in AFG (0.21, 95% CI = 0.003-0.39), while shared environmental factors were important for AFD (0.31, 95% CI = 0.15-0.46). Among men, genetic factors influenced variation in AFG but not in AFD and shared environmental factors influenced variation in AFD but not in AFG. Among women, shared environmental factors influenced variation in both AFD and AFG, but these environmental factors were not significantly correlated (rC  = 0.09).

CONCLUSIONS

Among Australian twins, age at first drink and age first gambled are influenced by distinct unique environmental factors, and the genetic and environmental underpinnings of both phenotypes differ in men and women.

A closer look at the evidence for sex differences in the genetic and environmental influences on gambling in the national longitudinal study of adolescent health: from disordered to ordered gambling

BACKGROUND AND AIMS

To reconcile an inconsistency in the disordered gambling literature by revisiting a previous study that claimed to find evidence for large gender differences in the magnitude of genetic and environmental influences.

DESIGN

Univariate structural equation twin models were fitted to decompose the variation in gambling behavior into additive genetic, shared environmental and unique environmental influences.

SETTING

United States.

PARTICIPANTS

Participants were 1196 same-sex and unlike-sex twins (18-28 years of age, 49% male, 51% female) from the National Longitudinal Study of Adolescent Health (Add Health).

MEASUREMENTS

Eight questions about normative and problematic gambling involvement were assessed by in-person interview. Although disordered gambling symptoms were assessed, the number of individuals who were administered these questions precluded twin analysis, including analysis of potential gender differences. Of the eight questions, only three were deemed usable for twin analysis-these were all questions about normative gambling involvement.

FINDINGS

Individual differences in (non-disordered) gambling involvement were explained completely by family [C = 38% (30-46%)] and unique environmental factors [E = 62% (54-70%)]. There was no evidence for genetic factors (A = 0), nor was there evidence for sex differences (Δχ(2) = 1.23, d.f. = 2, P = 0.54).

CONCLUSIONS

There appears to be no evidence for gender differences in the genetic contributions to disordered gambling. Family environment appears to play a significant role in explaining individual differences in (non-disordered) gambling involvement among emerging adults.

Shared genetic vulnerability for disordered gambling and alcohol use disorder in men and women: evidence from a national community-based Australian Twin Study

Disordered gambling (DG) will soon be included along with the substance use disorders in a revised diagnostic category of the Diagnostic and Statistical Manual of Mental Disorders DSM-5 called 'Substance Use and Addictive Disorders'. This was premised in part on the common etiologies of DG and the substance use disorders. Using data from the national community-based Australian Twin Registry, we used biometric model fitting to examine the extent to which the genetic liabilities for DG and alcohol use disorder (AUD) were shared, and whether this differed for men and women. The effect of using categorical versus dimensional DG and AUD phenotypes was explored, as was the effect of using diagnoses based on the DSM-IV and the proposed DSM-5 diagnostic criteria. The genetic correlations between DG and AUD ranged from 0.29 to 0.44. There was a significantly larger genetic correlation between DG and AUD among men than women when using dimensional phenotypes. Overall, about one-half to two-thirds of the association between DG and AUD was due to a shared genetic vulnerability. This study represents one of the few empirical demonstrations of an overlap in the genetic risk for DG and another substance-related addictive disorder. More research is needed on the genetic overlap between DG and other substance use disorders, as well as the genetic overlap between DG and other (non-substance-related) psychiatric disorders.

Modern Advances in Genetic Testing: Ethical Challenges and Training Implications for Current and Future Psychologists

The ethical implications for psychological practice of genetic testing are largely unexplored. Predictive testing can have a significant impact on health and well-being, and increasing numbers of individuals with knowledge of their risk for various disorders are likely to present for psychotherapy. In addition, more people will struggle with the decision of whether to obtain information regarding their genetic material. Psychologists will need to have the appropriate knowledge and clinical skills to effectively counsel this population. This article highlights the relevant ethical issues surrounding psychological treatment of individuals pursuing or considering undergoing genetic testing. These issues are extended to psychologists working in research, education, and policy domains. Recommendations for graduate training programs to facilitate current and future practitioner competence are also discussed.

Effects of sibship size and composition on younger brothers' and sisters' alcohol use initiation: findings from an Australian twin sample

BACKGROUND

The effects of sibship size and structure on delinquency are well established. Specifically, having a large family and many brothers has been shown to predict offending. However, despite strong links between delinquency and alcohol use, the contribution of sibship factors to drinking behaviors remains largely unexplored. The current study investigated the impact of sibship size and composition on younger brothers' and sisters' ages of drinking and intoxication onset.

METHODS

We employed a sample of 4,281 same-sex twins from the Australian Twin Register to examine whether (i) large sibship size facilitates earlier age at first drink (AFD) and age at first intoxication (AFI) in males and females, (ii) having many older brothers predicts earlier ages of AFD and AFI in males, and (iii) having many older brothers results in later AFD and AFI in females. We tested whether effects were moderated by parental divorce and alcohol misuse and mediated by familial religion.

RESULTS

Sibling effects were minimal before accounting for family context. However, when parental divorce and excessive parental drinking were included as moderators, sibling effects were significantly amplified among individuals from homes of divorce, and effects were strongest when siblings were close in age.

CONCLUSIONS

Strong close in age older sibling effects indicate that proximal sibling attitudes and behaviors about alcohol likely interact with structural factors to influence younger siblings' drinking. Sibship factors were much more influential in one population (individuals from homes of divorce) than another (respondents with a parental history of excessive drinking), suggesting that sibling effects vary depending on the type of co-occurring familial risk. Prevention efforts performed at the family level, and introduced before first use of alcohol, are likely to delay drinking initiation and help prevent future alcohol problems.

Investigating the influence of prenatal androgen exposure and sibling effects on alcohol use and alcohol use disorder in females from opposite-sex twin pairs

BACKGROUND

There are robust sex differences for alcohol phenotypes, with men reporting more drinking and alcohol use disorder (AUD) symptoms than women. However, the sources of these effects are not completely understood. Sex hormones, a substantial biological sex difference, exert neurobehavioral influences and are candidates for influencing sex differences in alcohol phenotypes. This study investigated the effects of prenatal androgens based on the hypothesis of prenatal hormone transfer, which posits that hormones from one twin influence the development of a cotwin.

METHODS

This study compared female twins from opposite-sex (OSF) and same-sex (SSF) pairs to investigate associations between prenatal androgens and alcohol phenotypes. Additional analyses distinguished prenatal and postnatal effects by comparing OSFs and SSFs with a close-in-age older (CAO) brother.

RESULTS

OSFs endorsed more lifetime AUD symptoms than SSFs (d = 0.14). Females with a CAO brother reported greater intoxication frequency (d = 0.35), hangover frequency (d = 0.24), typical drinking quantity (d = 0.33), and max drinks (i.e., the most drinks ever consumed in a 24-hour period; d = 0.29). Controlling for postnatal effects, OSFs still endorsed more lifetime AUD symptoms than SSFs with a CAO brother (d = 0.16).

CONCLUSIONS

Prenatal exposure to a male cotwin was associated with increases in AUD symptoms, above the effect of postnatal exposure to a male sibling. Prenatal exposure to a male cotwin was not associated with increases in other alcohol-related phenotypes, but postnatal exposure to older male siblings produced medium effect sizes for indicators of alcohol consumption. Sex differences in AUDs, but not alcohol use, may be partially due to the neurodevelopmental effects of prenatal androgens. However, sibling effects may be larger than any effect of prenatal androgen exposure.