Associations between genetic and prenatal factors and externalizing and internalizing psychopathology in childhood

Psychiatric disorders affect up to 25% of the population over the life course, and in 50% of cases, a person diagnosed with one will also be diagnosed with another. These conditions are highly comorbid, with many symptoms shared to varying degrees across disorders. Whereas disorders related to disinhibition—such as ADHD, conduct disorder, risk-taking, and substance use—make up the externalizing spectrum, disorders characterized by high levels of negative affectivity—such as major depressive disorder, posttraumatic stress disorder, and generalized anxiety disorder—make up the internalizing spectrum. Although these disorders and behaviors exert a significant toll of individual adjustment and society, their etiology is poorly understood.Previous research examining associations between environmental factors and externalizing traits report that psychosocial (e.g. socioeconomic status, parenting), prenatal factors (e.g., infections, alcohol or drug use, and exposure to certain medications), perinatal factors (e.g., pregnancy complications, surgery), and postnatal outcomes (e.g., low birth weight) may confer higher levels of externalizing and internalizing disorder prevalence. However, many of these studies have not simultaneously accounted for parental and child genetic predisposition to externalizing and internalizing disorders or pregnancy outcomes when estimating these associations.

The goal of this project is to better understand how pre, peri-, and postnatal factors contribute to externalizing and internalizing by accounting for genetic and psychosocial confounding (e.g., socio-economic outcomes).

This research will help clarify how early-life environments and inherited risks shape the development of externalizing and internalizing, potentially providing insights for future prevention and early intervention strategies.