Role of self-medication in the development of comorbid anxiety and substance use disorders: a longitudinal investigation

Arch Gen Psychiatry. 2011 Aug;68(8):800-7. doi: 10.1001/archgenpsychiatry.2011.75.

Abstract

Context: Self-medication of anxiety symptoms with alcohol, other drugs, or both has been a plausible mechanism for the co-occurrence of anxiety disorders and substance use disorders. However, owing to the cross-sectional nature of previous studies, it has remained unknown whether self-medication of anxiety symptoms is a risk factor for the development of incident substance use disorder or is a correlate of substance use.

Objective: To examine whether self-medication confers risk of comorbidity.

Design: A longitudinal, nationally representative survey was conducted by the National Institute on Alcohol Abuse and Alcoholism. The National Epidemiologic Survey on Alcohol and Related Conditions assessed DSM-IV psychiatric disorders, self-medication, and sociodemographic variables at 2 time points.

Setting: The United States.

Participants: A total of 34 653 US adults completed both waves of the survey. Wave 1 was conducted in 2001-2002, and wave 2 interviews occurred 3 years later (2004-2005).

Main outcome measures: Incident substance use disorders in participants with baseline anxiety disorders and incident anxiety disorders in those with baseline substance use disorders.

Results: Logistic regression analyses revealed that self-medication conferred a heightened risk of new-onset substance use disorders in those with baseline anxiety disorders (adjusted odds ratios [AORs], 2.50-4.99 [P < .01]). Self-medication was associated with an increased risk of social phobia (AOR in baseline alcohol use disorders, 2.13 [P = .004]; AOR in baseline drug use disorders, 3.17 [P = .001]).

Conclusions: Self-medication in anxiety disorders confers substantial risk of incident substance use disorders. Conversely, self-medication in substance use disorders is associated with incident social phobia. These results not only clarify several pathways that may lead to the development of comorbidity but also indicate at-risk populations and suggest potential points of intervention in the treatment of comorbidity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anxiety / complications
  • Anxiety / etiology*
  • Diagnosis, Dual (Psychiatry) / psychology*
  • Female
  • Health Surveys
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Risk Factors
  • Self Medication / adverse effects*
  • Substance-Related Disorders / complications
  • Substance-Related Disorders / etiology*