The impact of substance use disorders on recovery from bipolar depression: results from the systematic treatment enhancement program for Bipolar Disorder psychosocial treatment trial

© The Royal Australian and New Zealand College of Psychiatrists 2018. Objective: Up to 60% of patients with bipolar disorder develop a substance use disorder during their lifetime. The purpose of this paper was to assess the impact of substance use disorders on depression recovery among bipolar patients randomly assigned to different psychotropic medications and psychosocial interventions. We hypothesized that patients with a comorbid substance use disorder would benefit less from psychotherapy regardless of treatment intensity/length compared to patients without a comorbid substance use disorder. Method: We conducted post hoc analyses among bipolar disorder patients (n = 270) with and without comorbid substance use disorders enrolled in the Systematic Treatment Enhancement Program for Bipolar Disorder randomized psychosocial intervention trial. All patients entered during or shortly after the onset of a bipolar depressive episode. Logistic regression and Cox proportional hazard models were used to assess whether current or past substance use disorders moderated the response of patients to intensive psychosocial intervention or brief psychoeducation with collaborative care, operationalized as full recovery from an episode of bipolar depression. Results: Current comorbid substance use disorders significantly predicted likelihood of recovery (odds ratio = 2.25, p = 0.025) and time to recovery (odds ratio = 1.71, p = 0.006) from bipolar depression. We found that 74.5% of patients with a current substance use disorder, compared to 56.5% without a current substance use disorder, recovered from bipolar depression. Past substance use disorders did not predict likelihood of recovery or time to recovery. Current substance use disorders did not significantly moderate response to intensive psychotherapy versus collaborative care. Conclusion: Contrary to our hypotheses, bipolar disorder participants with a current comorbid substance use disorder were more likely to recover from psychosocial treatment for bipolar depression than patients without a current comorbid substance use disorder. If this finding is replicated, it has implications for the ordering of treatment for patients with comorbid bipolar disorder and substance use disorders.