We conducted a randomized comparison of dual-focus schema therapy with individual drug counseling as enhancements to the residential treatment of 105 substance-dependent patients with specific personality disorders versus those without. Both therapies were manual-guided and delivered for 6 months by experienced psychotherapists intensively trained and supervised with independent fidelity assessment. Using the Cox proportional hazards model, we found no psychotherapy differences in retention (days in treatment). Hierarchical linear modeling indicated that participants with personality disorders started with higher psychiatric, interpersonal, and dysphoria symptoms and that both therapies reduced symptoms in 6 months. Contrary to predictions, individual drug counseling resulted in more sustained reductions than did dual-focus schema therapy in several symptoms for several personality disorders. Our findings raised important questions about the added value of integrative or dual-focus therapies for co-occurring personality disorders and substance dependence relative to empirically supported therapies focused more specifically on addiction symptoms.