Does gabapentin lead to early symptom improvement in obsessive-compulsive disorder?

Author(s): Onder E, Tural U, Gokbakan M

Affiliation(s): Department of Psychiatry, Medical Faculty of Kocaeli University, Kocaeli, Turkey.

Publication date & source: 2008-09, Eur Arch Psychiatry Clin Neurosci., 258(6):319-23. Epub 2008 Feb 23.

Publication type: Randomized Controlled Trial

OBJECTIVE: The aim of this study was to compare efficacy of fluoxetine alone and co-administration of gabapentin and fluoxetine in patients with obsessive compulsive disorder (OCD). METHODS: Forty outpatients with a DSM-IV diagnosis of OCD were randomized to open label treatment, 20 of whom were treated with fluoxetine alone and the remaining 20 with fluoxetine plus gabapentin during 8 weeks. The severity was assessed by Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Clinical Global Impression (CGI). RESULTS: Final CGI-I and Y-BOCS scores were not significantly different in both groups. However, in repeated measures ANOVA, compared to fluoxetine group, we found significantly a better improvement in the fluoxetine plus gabapentin group at week 2 by means of YBOCS and CGI-I scores. Comparisons on weeks 4, 6 and 8 revealed no statistical differences between the groups. There was no significant difference of adverse effects between two groups. CONCLUSIONS: Adding gabapentin to fluoxetine in the treatment of OCD seems to shorten the time to onset of fluoxetine's anti-obsessive effect without a significant increase in adverse effects. In order to accelerate the clinical response, co-administration of fluoxetine and gabapentin may be a preferable strategy. On the other hand, further controlled studies are needed to support this finding.