Ashlee A. Moore

Age of onset and the subclassification of conduct/dissocial disorder

BACKGROUND Conduct Disorder (CD) is a markedly heterogeneous psychiatric condition. Moffitt (1993) proposed that subclassification of CD should be according to age of onset. Our goals were to compare childhood-onset and adolescent-onset CD in terms of differences in phenotypic risk factors, genetic analyses, and factors associated with the persistence of antisocial behavior into young adulthood. METHODS The data are from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and Young Adult Follow-Up (YAFU). Childhood-onset CD was defined as CD beginning at or before age 11. Adolescent-onset CD was defined as having CD onset between ages 14 and 17. These subgroups were compared on ADHD, young adult antisocial behavior (ASB), family dysfunction, and parental depression. Genetic analyses compare childhood-onset and adolescent-onset CD, as well as their cooccurrence with ADHD and ASB. Finally, predictors of persistence were examined. RESULTS Childhood-onset CD was significantly associated with ADHD, ASB, family dysfunction, and parental depression. Adolescent-onset CD was marginally associated with parental depression (p = .05) but not with any of the other risk factors. Univariate genetic models showed that both childhood-onset and adolescent-onset CD involve a large genetic liability accounting for 62% and 65% of the variance, respectively. A common genetic factor (as well as an ADHD-specific factor) accounted for the cooccurrence of childhood-onset CD and ADHD. The cooccurrence of childhood-onset CD and ASB are reflected by a common genetic factor with genetic specific effects on ASB. There was no etiological link between adolescent-onset CD and either ADHD or ASB. Both ADHD and family dysfunction were significantly associated with the persistence of antisocial behavior into young adulthood. CONCLUSIONS Phenotypic findings differentiated between childhood-onset and adolescent-onset CD. ADHD and family dysfunction predicted persistence of antisocial behavior into young adulthood.

Psychiatric outcomes of bullying victimization: a study of discordant monozygotic twins

BACKGROUND Bullying victimization in childhood is associated with a broad array of serious mental health disturbances, including anxiety, depression, and suicidal ideation and behavior. The key goal of this study was to evaluate whether bullying victimization is a true environmental risk factor for psychiatric disturbance using data from 145 bully-discordant monozygotic (MZ) juvenile twin pairs from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and their follow-up into young adulthood. METHOD Since MZ twins share an identical genotype and familial environment, a higher rate of psychiatric disturbance in a bullied MZ twin compared to their non-bullied MZ co-twin would be evidence of an environmental impact of bullying victimization. Environmental correlations between being bullied and the different psychiatric traits were estimated by fitting structural equation models to the full sample of MZ and DZ twins (N = 2824). Environmental associations were further explored using the longitudinal data on the bullying-discordant MZ twins. RESULTS Being bullied was associated with a wide range of psychiatric disorders in both children and young adults. The analysis of data on the MZ-discordant twins supports a genuine environmental impact of bullying victimization on childhood social anxiety [odds ratio (OR) 1.7], separation anxiety (OR 1.9), and young adult suicidal ideation (OR 1.3). There was a shared genetic influence on social anxiety and bullying victimization, consistent with social anxiety being both an antecedent and consequence of being bullied. CONCLUSION Bullying victimization in childhood is a significant environmental trauma and should be included in any mental health assessment of children and young adults.

Potentially Traumatic Events, Personality, and Risky Sexual Behavior in Undergraduate College Students.

Objective: Impulsivity and extraversion have demonstrated associations with risky sexual behavior (RSB) and potentially traumatic events (PTEs). In addition, interpersonal trauma appears to be associated with RSB, but research on the relationship between RSB and noninterpersonal PTEs (e.g., accidental) is lacking. The current study aims to investigate the relationships between personality (i.e., impulsivity, extraversion), RSB and multiple types of PTEs (i.e., accidental, physical, or sexual). Method: Personality and demographic characteristics were assessed during participants’ (N = 970) first semester of college, past-12 month PTEs and RSB were assessed during the second semester of participants’ junior year. Multiple linear regression was used to examine the relationship between PTEs, personality factors, and RSB. Analyses were also conducted to examine the potential mediating effect of interpersonal PTEs on the relationship between personality and RSB. Results: Impulsivity and extraversion were significantly positively associated with RSB. Both physical and sexual PTEs, but not accidental PTEs, were also significantly positively associated with RSB. Sexual PTEs significantly mediated the relationship between impulsivity and RSB. Conclusions: This is the first study to date to simultaneously examine the relationship between personality, RSB, and types of PTEs in a large sample of young adults. Exposure to interpersonal trauma appears to be a salient factor in the relationship between personality, specifically impulsivity, and RSB. These results indicate that college students may benefit from education regarding the potential negative outcomes of RSB, and that individuals with a history of interpersonal PTEs may be at increased risk for sexual risk taking.

Genetic and Environmental Contributions of Negative Valence Systems to Internalizing Pathways

The genetic and environmental contributions of negative valence systems (NVS) to internalizing pathways study (also referred to as the Adolescent and Young Adult Twin Study) was designed to examine varying constructs of the NVS as they relate to the development of internalizing disorders from a genetically informed perspective. The goal of this study was to evaluate genetic and environmental contributions to potential psychiatric endophenotypes that contribute to internalizing psychopathology by studying adolescent and young adult twins longitudinally over a 2-year period. This report details the sample characteristics, study design, and methodology of this study. The first wave of data collection (i.e., time 1) is complete; the 2-year follow-up (i.e., time 2) is currently underway. A total of 430 twin pairs (N = 860 individual twins; 166 monozygotic pairs; 57.2% female) and 422 parents or legal guardians participated at time 1. Twin participants completed self-report surveys and participated in experimental paradigms to assess processes within the NVS. Additionally, parents completed surveys to report on themselves and their twin children. Findings from this study will help clarify the genetic and environmental influences of the NVS and their association with internalizing risk. The goal of this line of research is to develop methods for early internalizing disorder risk detection.

Life course persistent and adolescence limited conduct disorder in a nationally representative US sample: prevalence, predictors, and outcomes

PurposeThe course of conduct disorder (CD) is heterogeneous. Moffitt proposed the heuristic of life course persistent (LCP) and adolescence limited (AL) to differentiate etiologically distinct forms of antisocial behavior (AB), each with distinct predictors and consequences, although a few studies have assessed this demarcation within the context of CD. The objective of this study was to apply Moffitt’s taxonomy in a nationally representative US sample to investigate the prevalence, predictors, and outcomes of LCP and AL CD.MethodsData come from the Collaborative Psychiatric Epidemiology Studies, a set of population-based nationally representative cross-sectional surveys (N = 20,130). Predictors included harsh discipline, maternal and paternal closeness, poverty in childhood, history of learning disability, parental deviance, and nativity. Outcomes included substance use, employment status, education attainment, marital status, income level, and self-rated mental and physical health.ResultsThe prevalence of LCP and AL CD was 0.5 and 4.6%, respectively, for females, and 1.9 and 5.1%, respectively, for males. Low childhood SES [Odds Ratio (OR) = 3.49], lack of maternal closeness (OR = 2.50), and history of harsh discipline (OR = 2.17) increased odds of LCP group membership. The LCP group had higher odds of developing substance use disorders (OR = 2.00) relative to AL.ConclusionsLCP CD is more strongly influenced by childhood environment and confers increased odds for substance use problems in adulthood relative to AL CD.

Substance Use and Depression Symptomatology: Measurement Invariance of the Beck Depression Inventory (BDI-II) among Non-Users and Frequent-Users of Alcohol, Nicotine and Cannabis

Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual’s substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II) in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups

Shared genetic and environmental influences on early temperament and preschool psychiatric disorders in Hispanic twins.

OBJECTIVE Despite an increasing recognition that psychiatric disorders can be diagnosed as early as preschool, little is known how early genetic and environmental risk factors contribute to the development of psychiatric disorders during this very early period of development. METHOD We assessed infant temperament at age 1, and attention deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and separation anxiety disorder (SAD) at ages 3 through 5 years in a sample of Hispanic twins. Genetic, shared, and non-shared environmental effects were estimated for each temperamental construct and psychiatric disorder using the statistical program MX. Multivariate genetic models were fitted to determine whether the same or different sets of genes and environments account for the co-occurrence between early temperament and preschool psychiatric disorders. RESULTS Additive genetic factors accounted for 61% of the variance in ADHD, 21% in ODD, and 28% in SAD. Shared environmental factors accounted for 34% of the variance in ODD and 15% of SAD. The genetic influence on difficult temperament was significantly associated with preschool ADHD, SAD, and ODD. The association between ODD and SAD was due to both genetic and family environmental factors. The temperamental trait of resistance to control was entirely accounted for by the shared family environment. CONCLUSIONS There are different genetic and family environmental pathways between infant temperament and psychiatric diagnoses in this sample of Puerto Rican preschool age children.

The relationship between on-campus service utilization and common mental health concerns in undergraduate college students.

Little research exists into the trends associated with on-campus service utilization for mental health concerns of college students. Rates of broad service utilization exist, but no published study has examined the direct relationship between a range of common mental health symptoms and on-campus service utilization. The aims of the present study are to explore (1) which common mental health concerns are associated with specific on-campus service utilization in undergraduate students and (2) whether endorsement of more mental health concerns will predict a higher number of services utilized. Data were utilized from 3,734 undergraduates at a large (more than 20,000 undergraduates), urban university (Mage = 19.94 years, SD = 0.55 years; female = 66%). Four on-campus services (University Counseling Services, University Health Services, The Wellness Resource Center, and Disability Support Services) were regressed onto mental health concerns associated with symptoms of three disorders (anxiety, depression, alcohol use disorder [AUD]) and two mental health risk factors (stressful life events [SLEs], antisocial behaviors [ASBs]). AUD symptoms predicted the most overall and specific service utilization, followed by depression symptoms and SLEs. Anxiety symptoms and ASBs were not significant predictors when combined with other variables. This is the first study to investigate trends specific to on-campus college student service utilization. Findings will be helpful to mental health professionals on similar college campuses by providing insight into programming and outreach initiatives for these or related services. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Opportunities for an enhanced integration of neuroscience and genomics

Neuroimaging and genetics are two rapidly expanding fields of research. Thoughtful integration of these areas is critical for ongoing large-scale research into the genetic mechanisms underlying brain structure, function, and development. Neuroimaging genetics has been slow to evolve relative to psychiatric genetics research, and some may be unaware that new statistical methods allow for the genomic analysis of more modestly-sized imaging samples. We present a broad overview of the extant imaging genetics literature, provide an interpretation of the major problems surrounding the integration of neuroimaging and genetics, discuss the influence and impact of genetics consortia, and suggest statistical genetic analyses that expand the repertoire of imaging researchers amassing rich behavioral data in modestly-sized samples. Specific attention is paid to the creative use of polygenic risk scoring in imaging genetic analyses, with primers on the most current risk scoring applications.

Resting Heart Rate Variability (HRV) in Adolescents and Young Adults from a Genetically-Informed Perspective

Reduced heart rate variability (HRV) is associated with cardiac morbidity, mortality, and negative psychopathology. Most research concerning genetic influences on HRV has focused on adult populations, with fewer studies investigating the developmental period of adolescence and emerging adulthood. The current study estimated the genetic and environmental contributions to resting HRV in a sample of twins using various HRV time domain metrics to assess autonomic function across two different time measurement intervals (2.5- and 10-min). Five metrics of resting HRV [mean interbeat interval (IBI), the standard deviation of normal IBIs (SDNN), root square mean of successive differences between IBIs (RMSSD), cardiac vagal index (CVI), and cardiac sympathetic index (CSI)] were assessed in 421 twin pairs aged 14–20 during a baseline electrocardiogram. This was done for four successive 2.5-min intervals as well as the overall 10-min interval. Heritability (h2) appeared consistent across intervals within each metric with the following estimates (collapsed across time intervals): mean IBI (h2 = 0.36–0.46), SDNN (h2 = 0.23–0.30), RMSSD (h2 = 0.36–0.39), CVI (h2 = 0.37–0.42), CSI (h2 = 0.33–0.46). Beyond additive genetic contributions, unique environment also was an important influence on HRV. Within each metric, a multivariate Cholesky decomposition further revealed evidence of genetic stability across the four successive 2.5-min intervals. The same models showed evidence for both genetic and environmental stability with some environmental attenuation and innovation. All measures of HRV were moderately heritable across time, with further analyses revealing consistent patterns of genetic and environmental influences over time. This study confirms that in an adolescent sample, the time interval used (2.5- vs. 10-min) to measure HRV time domain metrics does not affect the relative proportions of genetic and environmental influences.