The Structure of Genetic and Environmental Risk Factors for Common Psychiatric and Substance Use Disorders in Men and Women

Abstract

HIGH LEVELS of comorbidity are consistently seen for psychiatric and substance use disorders.^1,2 Such a pattern suggests that many risk factors for psychopathology are not disorder specific, a contention supported by numerous studies.^3-5 This observed pattern of comorbidity indicates that the broad array of common psychiatric disorders may be explained more parsimoniously by a small number of underlying factors. Recently, 3 large epidemiological studies have suggested that the most important of these factors reflect the broad groupings of internalizing and externalizing disorders^6-8 (although 2 of these studies^7,8 suggest that the internalizing factor might itself be divisible into subfactors).