Background and objectives: The association between substance use disorders (SUDs) and mental illness (MI) has been well established. Previous studies reporting this association in various clinical populations have not taken into account former substance use. This may be important as increased prevalence of substance use among individuals with MI may partially explain the strong association between SUDs and MI.
Methods: In this study we included only individuals with previous substance use and explored the association between lifetime diagnosis of MI and transition from substance use to SUDs. Analyses were conducted across six different categories of substances (alcohol, nicotine, cannabis, cocaine, hallucinogens, inhalants) based on a large representative US sample, the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC, n = 43,093).
Results: Lifetime diagnoses of any MI, and particularly personality disorders and psychotic disorders, were found to be associated with higher prevalence of transition from substance use to SUDs across most categories of substances. This association was particularly strong for nicotine (adjusted OR = 2.95 (2.72-3.20)).
Conclusions and scientific significance: This cross-sectional study expands on previous research by highlighting the association between lifetime diagnosis of any MI and increased rates of transition from substance use to SUDs across a range of substances. Longitudinal studies exploring temporal effects of this association are further needed.
Copyright © American Academy of Addiction Psychiatry.