Integrating the study of personality and psychopathology in the context of gene-environment correlations across development

Common genetic and environmental bases of the mental disorders and personality traits: Special focus on the hierarchical model of psychopathology and NEO-PI-R facets

OBJECTIVE

This study examined whether phenotypic correlations between psychopathological dimensions and personality traits of different hierarchical levels originate from common genetic and environmental sources of variance.

METHOD

Participants were 386 monozygotic and 204 dizygotic twins. The Psychiatric Diagnostic Screening Questionnaire (PDSQ) was applied along with the Revised NEO Personality Inventory (NEO-PI-R). The results of the CFA confirmed the hypothesis of the internalizing and externalizing dimensions underlying PDSQ scales.

RESULTS

The results indicated a significantly greater role of genetic compared to environmental factors in the relationship between internalizing psychopathology and personality traits. Facets of neuroticism showed positive genetic links with internalizing disorders, while negative genetic links were shown for all facets of extraversion except excitement-seeking, competence, self-discipline, achievement striving, actions, and trust. Lower-order personality traits were shown to be associated with internalizing disorders more intensively than the broader domains to which they belong, both at the phenotypic and genetic levels.

CONCLUSIONS

High neuroticism, together with several facets from the domain of extraversion and conscientiousness seems to represent an increased genetic susceptibility to the disorders from the internalizing spectrum. Results also suggest that specific environmental factors which are not shared with personality traits contribute to the internalizing symptoms.

Promoting Empathy and Affiliation in Relationships (PEAR) study: protocol for a longitudinal study investigating the development of early childhood callous-unemotional traits

INTRODUCTION

Children with callous-unemotional (CU) traits are at high lifetime risk of antisocial behaviour. Low affiliation (ie, social bonding difficulties) and fearlessness (ie, low threat sensitivity) are proposed risk factors for CU traits. Parenting practices (eg, harshness and low warmth) also predict risk for CU traits. However, few studies in early childhood have identified attentional or physiological markers of low affiliation and fearlessness. Moreover, no studies have tested whether parenting practices are underpinned by low affiliation or fearlessness shared by parents, which could further shape parent-child interactions and exacerbate risk for CU traits. Addressing these questions will inform knowledge of how CU traits develop and isolate novel parent and child targets for future specialised treatments for CU traits.

METHODS AND ANALYSIS

The Promoting Empathy and Affiliation in Relationships (PEAR) study aims to establish risk factors for CU traits in children aged 3-6 years. The PEAR study will recruit 500 parent-child dyads from two metropolitan areas of the USA. Parents and children will complete questionnaires, computer tasks and observational assessments, alongside collection of eye-tracking and physiological data, when children are aged 3-4 (time 1) and 5-6 (time 2) years. The moderating roles of child sex, race and ethnicity, family and neighbourhood disadvantage, and parental psychopathology will also be assessed. Study aims will be addressed using structural equation modelling, which will allow for flexible characterisation of low affiliation, fearlessness and parenting practices as risk factors for CU traits across multiple domains.

ETHICS AND DISSEMINATION

Ethical approval was granted by Boston University (#6158E) and the University of Pennsylvania (#850638). Results will be disseminated through conferences and open-access publications. All study and task materials will be made freely available on lab websites and through the Open Science Framework (OSF).

Genetic versus environmental influences on callous-unemotional traits in preadolescence: The role of parenting and parental psychopathology

Children with callous-unemotional (CU) traits are at risk for severe conduct problems. While CU traits are moderately heritable, parenting also predicts risk. However, few studies have investigated whether parenting factors (e.g., acceptance, conflict, parental psychopathology) moderate the etiology of CU traits, while accounting for gene-environment correlations. To address this knowledge gap, we used data from 772 twin pairs from the Adolescent Brain and Cognitive Development Study to test bivariate models that explored overlapping etiological influences on CU traits and child reports of their parenting environment. We also used gene-by-environment interaction models to test whether parenting moderated genetic versus environmental influences. There were no overlapping etiological influences on CU traits and parental acceptance, but modest genetic and non-shared environmental overlap between CU traits and family conflict. Parental acceptance and psychopathology moderated non-shared environmental influences, with stronger non-shared environmental influences on CU traits among children who experienced lower parental acceptance and greater parental psychopathology. Family conflict only moderated environmental influences when models did not covary for conduct problems. Parental acceptance and parental psychopathology may be specific environmental protective and risk factors for CU traits, whereas family conflict may represent a general environmental risk factor for both CU traits and conduct problems.

Family Experiences and Parent Personality as Antecedents of Pubertal Timing in Girls and Boys

Pubertal timing may be influenced by typical variations in early family environmental events, but questions remain concerning the roles of specific parenting factors, developmental age of exposure to events, moderation by child temperament, and comparability of effects for girls and boys. This study focused on these questions utilizing longitudinal data from 733 same-sex twins (45% girls) in the U.S.; family context was measured at ages 1-3, 4-5, and 6-7 years and pubertal status was assessed annually via self-report at ages 9-15, enabling estimates of pubertal timing. Home environment at ages 4-5 years predicted pubertal timing better than home environment at other ages for both girls and boys, but parent personality was more predictive than home experiences (e.g., divorce, parental harshness, family conflict). Thus, effects of family environment must be considered within the context of parent characteristics, encouraging caution in implicating early environmental experiences as direct influences on early pubertal timing.