Is deep brain stimulation effective and safe for patients with obsessive compulsive disorder and comorbid bipolar disorder?

Background: Deep brain stimulation (DBS) is an effective treatment for refractory obsessive-compulsive disorder (OCD). Bipolar disorder (BD) is generally considered a contra-indication for DBS due to frequently reported transient impulsivity or (hypo)mania. Objective: The present study is the first study to examine effectiveness and safety of DBS for patients with OCD and BD. Methods: Five consecutive patients suffering from treatment-refractory OCD with comorbid BD (I or II) underwent DBS of the ventral anterior limb of the internal capsule (vALIC). We examined effectiveness of DBS on symptoms of OCD and depression, using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and Hamilton Depression Rating Scale (HAM-D). We monitored side-effects, in particular DBS-induced (hypo)manic symptoms, using the Young mania rating scale (YMRS). Results: Follow-up time ranged between 15 and 68 months. vALIC-DBS led to a significant improvement of OCD and depressive symptoms. Mean Y-BOCS score decreased from 36.8 (SD 2.4) to 22.4 (SD 9.4). Mean HAM-D score dropped from 24.2 (SD 8.6) to 16.5 (SD 11.3). Transient hypomanic symptoms were observed in 4 out of 5 patients and in 1 patient, hypomanic symptoms resolved by adjusting stimulation and medication. Changes in YMRS scores were not significant. Hypomanic symptoms did not result in admission or lasting adverse consequences. Conclusion: DBS effectively alleviates symptoms of OCD and depression in patients with OCD and BD but there is a large risk of developing transient hypomanic symptoms. Altogether, comorbid BD should not be considered as an absolute contra-indication for DBS in OCD patients with comorbid BD, but patients should be monitored carefully during optimization and follow-up of DBS.