Effects of major depression and attention deficit/hyperactivity disorder on the outcome of treatment for cocaine-dependence

摘要

Co-occurring psychiatric disorders have been associated with poor prognosis among substance dependent patients, but few studies have examined this association among patients with cocaine dependence (CD). Baseline characteristics and treatment outcome were compared between cocaine-dependent patients with major depression (MDD) (N = 66), attention-deficit/hyperactivity disorder (ADHD) (N = 53), or cocaine dependence without comorbid disorders (CD alone) (N = 48), who had been randomized to the placebo arms of clinical trials of venlafaxine, methylphenidate, and gabapentin, respectively. The three groups differed significantly in racial makeup, with more Caucasians and Hispanics among patients with MDD or ADHD, and more African Americans among those with CD alone. The groups did not differ significantly in treatment retention, with retention rates ranging from 42–47%, or in the rates of achieving 2 consecutive weeks of urine-confirmed abstinence, with rates ranging from 40–50%. Using logistic regression for repeated measures with general estimating equations, modeling the likelihood of a cocaine positive week over time in treatment, diagnostic group was found to interact with the baseline level of cocaine use and time. Among cocaine dependent patients who achieved abstinence at baseline, the groups with MDD or ADHD had better outcome over time than those with CD alone. However, among patients with cocaine positive urines at baseline, MDD or ADHD were associated with poor outcome compared to patients with CD alone. The findings suggest that diagnosis and treatment of co-occurring disorders such as depression and ADHD may be an important component of treatment planning for cocaine dependence, and that baseline level of cocaine use should be included as a covariate in studies evaluating the impact of such treatment.