Dimensional Psychopathology and Neurostructural Variation during Development: A Multi-Method Investigation
Durham, Everett Leighton
The comorbid, dimensional nature of psychopathology seems to be mirrored in related neural substrates, as studies have found similar neural mechanisms to be shared across multiple mental health disorders. While the traditional approach to studying psychopathology involves a categorical, case-control approach, there is a growing body of literature proposing that psychopathology can be conceptualized as a hierarchy of dimensional symptom domains. Further, these symptom dimensions can be related to neurostructural measures to identify common and unique neural substrates across domains of psychopathology. Previous studies using such a dimensional approach have shown inverse associations between psychopathology dimensions and gray matter volume (GMV). However, the majority of studies have focused on samples with broad age ranges, which may obscure developmental differences, and used univariate analytical approaches, which do not allow for the simultaneous investigation of brain-behavior relationships. The current study addresses these limitations and builds upon prior work through the examination of associations between regional GMV and psychopathology through two different statistical approaches and in a large sample of children with a narrowly defined age range. We used data from 9,607 children 9 to 10 years of age collected as part of the Adolescent Brain Cognitive DevelopmentSM Study (ABCD Study®). A bifactor model identified a general psychopathology factor that reflects common variance across disorders and specific factors representing internalizing symptoms, ADHD symptoms, and conduct problems. Brain volume was acquired using 3T MRI. In Study 1, univariate structural equation modeling (SEM) analysis was conducted and revealed nearly global inverse associations between regional GMVs and general psychopathology and conduct problems, with associations also found for ADHD symptoms (pfdr-values ≤ .048). In Study 2, multivariate partial least squares (PLS) analysis was conducted and again demonstrated that higher levels of general psychopathology, conduct problems, and ADHD symptoms are associated with smaller global brain volume. Age, sex, and race were included as covariates in all analyses. These findings together suggest that globally smaller GMVs are a nonspecific risk factor for general psychopathology, and possibly for conduct problems and ADHD as well.