Minocycline Combination Therapy with Fluvoxamine in Moderate-to-severe Obsessive-compulsive Disorder: A Placebo-controlled, Double-blind, Randomized Trial

Aim: Several lines of evidence implicate glutamatergic dysfunction in the pathophysiology of obsessive-compulsive disorder (OCD), presenting this neurotransmitter as a target for the development of novel pharmacotherapy. The objective of this study was to assess the efficacy of minocycline as an augmentative agent to fluvoxamine in the treatment of patients with OCD.

Methods: One hundred and two patients with the diagnosis of moderate-to-severe OCD were recruited to this study. A randomized double-blind trial was designed and patients received either L-carnosine or placebo as adjuvant to fluvoxamine for 10 weeks. The patients randomly received either minocycline 100 mg twice per day or placebo for 10 weeks. All patients received fluvoxamine (100 mg/day) for the first 4 weeks, followed by 200 mg/day for the rest of the trial, regardless of their treatment groups. Participants were evaluated using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). The main outcome measure was to assess the efficacy of minocycline in improving the OCD symptoms.

Results: General linear model repeated measures demonstrated significant effect for time × treatment interaction on the Y-BOCS total scores, F(1.49, 137.93) = 7.1, P  = 0.003, and Y-BOCS Obsession subscale score, F(1.54, 141.94) = 9.72, P = 0.001, and near significant effect for the Y-BOCS Compulsion subscale score, F(1.27, 117.47) = 2.92, P  = 0.08. A significantly greater rate of partial and complete response was observed in the minocycline group (P < 0.001). The frequency of side-effects was not significantly different between the treatment arms.

Conclusion: The results of this study suggest that minocycline could be a tolerable and effective adjuvant in the management of patients with OCD.