Are Personality Traits Familial Risk Factors for Substance Use Disorders? Results of a Controlled Family Study

OBJECTIVE: The well-documented association between maladaptive personality traits and substance use disorders has given rise to diverse explanatory models. In this investigation the authors examined one such explanation, that certain personality traits are familial risk factors for the development of substance abuse or dependence. METHOD: Data were collected from a controlled family study using direct diagnostic interviews. The Multidimensional Personality Questionnaire was used to assess the personality traits of 325 probands, 205 of whom had diagnoses of substance abuse or dependence, and 262 of their first-degree relatives. RESULTS: Probands with substance use disorders scored higher on alienation and negative emotionality than did probands without substance use disorders, and they scored lower on control, harm avoidance, and constraint. Relatives with substance use disorders also differed from relatives without these conditions on several of these same dimensions. To examine whether such personality traits could be conceptualized as familial risk factors for substance use disorders, a second set of analyses were limited to relatives without substance use disorders themselves but varying in terms of family history for these conditions. These groups of relatives did not differ significantly from each other on any of the identified personality traits. CONCLUSIONS: These findings argue for caution in characterizing the personality correlates of substance use disorders as representing familial or heritable risk factors.