Psychological Treatment of Obsessive-Compulsive Disorder in Patients with Major Depression: A Pilot Randomized Controlled Trial

Objective: To examine the efficacy of cognitive-behavioural therapy (CBT) for obsessive-compulsive disorder (OCD) in patients with comorbid major depressive disorder (MDD).Method: Participants ( n = 29) diagnosed with comorbid OCD and MDD were randomized to receive standard CBT for OCD or integrated CBT that included an exclusive focus on treating MDD in the first phase of treatment and OCD in the second phase of treatment.Results: Both treatments resulted in statistically significant improvements in OCD and MDD symptoms. Treatment effects and recovery rates in the intent-to-treat sample were lower in both treatments, compared with past studies that excluded patients with MDD. However, among treatment completers, both treatments resulted in statistically significant and clinically meaningful improvements in OCD and MDD symptoms.Conclusions: CBT holds promise as an efficacious treatment for people with comorbid OCD and MDD. The high treatment dropout rate with comorbid patients suggests that additional treatment strategies are required to enhance retention and optimize clinical outcomes.