Baseline characteristics and treatment outcomes in prescription opioid dependent patients with and without co-occurring psychiatric disorder

Background: Given the growing prevalence of prescription opioid dependence and the considerable rates of additional psychopathology in drug dependence, we examined the association between the presence of a co-occurring Axis I psychiatric disorder and sociodemographic and clinical characteristics in this secondary analysis of patients entering a treatment study for dependence on prescription opioids. Treatment outcomes were also compared. Methods: Patients dependent on prescription opioids participated in a multi-site, two-phase, randomized, controlled trial to assess different lengths of buprenorphine-naloxone pharmacotherapy and different intensities of counseling (Clinicaltrials.gov identifier: NCT00316277). Among the 653 participants entering the first phase of the trial, 360 entered the second phase, receiving 12 weeks of buprenorphine-naloxone treatment; they are reported here. Half of those participants (180/360) had a current co-occurring psychiatric disorder in addition to substance dependence. Results: Sociodemographic characteristics were similar overall between those with and without a co-occurring psychiatric disorder, but women were 1.6 times more likely than men to have a co-occurring disorder. On several clinical indicators at baseline, participants with a co-occurring disorder had greater impairment. However, they had better opioid use outcomes at the conclusion of 12 weeks of buprenorphine-naloxone stabilization than did participants without a co-occurring disorder. Conclusions: Prescription opioid-dependent patients with a co-occurring psychiatric disorder had a better response to buprenorphine-naloxone treatment despite demonstrating greater impairment at baseline. Additional research is needed to determine the mechanism of this finding and to adapt treatments to address this population.