REVIEW OF: Sahraian A et al, CNS Spectr 2021;1–5

TYPE OF STUDY: Randomized, double-blind, placebo-controlled clinical trial

SSRIs are first-line meds for obsessive-compulsive disorder (OCD), but they may pose risks of mania and rapid cycling when the patient also has bipolar disorder (BD). These conditions overlap more often than expected by chance, but only one controlled trial has looked at how to treat OCD in BD (it was positive and involved topiramate). This eight-week study tested quetiapine for obsessive-compulsive symptoms in patients with stable BD.

Participants had bipolar I with active OCD but were not in a mood episode. All were on lithium and clonazepam and no other psychotropics. Although they had no formal diagnosis of OCD, participants scored as moderate to severe (≥ 17) on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS).

In total, 47 adults entered the study after excluding other psychiatric, substance use, and medical diseases. Forty completed the trial, of which half received placebo and half quetiapine. Doses were increased until symptoms resolved or patients couldn’t tolerate more. Patients completed standard clinician-rated scales for OCD (Y-BOCS), mania (Young Mania Rating Scale [YMRS]), and depression (Hamilton Depression Rating Scale [HDRS]) at weeks zero, four, and eight.

The Y-BOCS score was the main outcome measure. On average, it fell by 9.1 in the quetiapine group and 0.3 in the placebo group. Half of the quetiapine group had a significant response (> 34% decrease in Y-BOCS), compared with 5% of the placebo group. Average quetiapine dose was 325 mg, although the dose range wasn’t reported. All patients remained euthymic during the trial based on standard clinician-rated scales (YMRS and HDRS).

Of the 47 study participants, seven dropped out, none for reasons associated with quetiapine. Those on quetiapine were 2.3 times more likely to report side effects (eg, drowsiness, increased appetite, constipation, orthostasis).

TCPR’S TAKE
Although difficult to tolerate, quetiapine may help when OCD is causing significant impairment in patients with BD. It made a difference in this study, bringing Y-BOCS scores from moderate-severe to mild.