Biological approaches to treatment-resistant obsessive compulsive disorder.

Biological approaches to the patient with treatment-resistant obsessive compulsive disorder are briefly reviewed. The most commonly employed strategy involves combining a potent serotonin reuptake inhibitor (SRI) (e.g., clomipramine or fluvoxamine) with another medication that may exert effects on the brain serotonin system. Open-label reports regarding the addition of tryptophan, fenfluramine, lithium, or buspirone to ongoing SRI therapy of obsessive compulsive disorder are encouraging. However, the anti-obsessive compulsive efficacy of SRI-lithium and SRI-buspirone combination therapy has not been confirmed in recent controlled trials. Preliminary evidence suggests that addition of neuroleptic may benefit SRI-refractory obsessive compulsive disorder patients who have a comorbid chronic tic disorder. Other biological approaches (e.g., electroconvulsive therapy and psychosurgery) are considered in terms of their narrowly defined roles in the treatment of patients with SRI-resistant obsessive compulsive disorder. Finally, an algorithm is proposed for those patients with obsessive compulsive disorder who fail to respond to an adequate trial with a potent SRI.