Prevalence of psychiatric disorders among young injection drug users.

BACKGROUND: Studies of individuals in treatment for substance use have found high rates of psychiatric disorders, however little is known about the mental health of drug users not in treatment. This study aimed to assess the prevalence of lifetime and recent substance use and psychiatric disorders among young injection drug users (IDU) outside of a treatment setting.

METHODS: Participants were recruited through outreach and respondent-driven sampling. Trained interviewers administered the Psychiatric Research Instrument for Substance and Mental Disorders. Interviews were conducted at two field stations operated by Community Outreach Intervention Projects in Chicago. Participants were 570 young adults (18-25 years) who injected drugs in the previous 30 days. Heroin was the primary drug used in this sample. Past 12-month and lifetime substance use disorders and primary and substance-induced mental disorders were based on DSM-IV diagnostic criteria.

RESULTS: Nearly all participants met the criteria for heroin dependence. Multiple substance use disorders were common; cannabis was the most common substance involved after heroin, followed by alcohol and cocaine. Major depression, alcohol dependence, antisocial personality disorder, and borderline personality disorder were highly prevalent. Other psychiatric disorders were observed at levels consistent with other young adult samples.

CONCLUSIONS: Young IDU experience major depression, alcohol dependence, anti-social personality disorder, and borderline personality disorder at high rates, and multiple substance use disorders are common. Anxiety disorders in this population appear to be similar in prevalence to young adults in general.