Anxiety disorders moderate the association between externalizing problems and substance use disorders: data from the National Comorbidity Survey-Revised.

Anxiety disorders and externalizing problems are both associated with substance use disorders. However, the nature of this relationship remains unclear. To examine whether presence of an anxiety disorder changes the association between externalizing problems (conduct disorder, oppositional defiant disorder, and attention deficit hyperactivity disorder) and substance use disorders, we analyzed data from the National Comorbidity Survey-Replication, which is based on a nationally representative sample of 9282 English-speaking adults. Presence of externalizing problems was associated with an increased odds for alcohol abuse (OR: 6.7, CI: 5.6-8.1), alcohol dependence (OR: 7.6, CI: 5.9-9.6), substance abuse (OR: 9.9, CI: 8.1-12.2), and substance dependence (OR: 13.1, CI: 9.6-17.8). Similarly, anxiety disorders were associated with increased odds for substance use disorders. The highest association was found between post-traumatic stress disorder and substance use disorder (OR: 9.2, CI: 5.4-15.5). Individuals who met diagnostic criteria for an anxiety disorder and externalizing problems showed consistently and significantly lower odds for substance use problems than subjects with externalizing problems without a comorbid anxiety disorder. The results suggest that presence of any anxiety disorder reduces the association between externalizing problems and substance use disorders, possibly because the fear of bodily symptoms prevents individuals with externalizing problems from engaging in drug-seeking behaviors.