Psychiatric Times 
July 2005
Vol. XXII
Issue 8
Obsessive-compulsive disorder is a severe, chronic condition that affects 2% to 3% of the U.S. population, or 4 million to 7 million people (Weissman et al., 1994). It is characterized by recurrent thoughts, images, feelings or behaviors that persist against the patient's wishes and is usually accompanied by severe anxiety and marked impairment of function.
Obsessive-compulsive disorder was listed as the 10th leading cause of disability worldwide by a World Health Organization study. The total cost of the disorder in the United States is estimated to be over $8 billion (Murray and Lopez, 1996).
Serotonin reuptake inhibitors are the first line of pharmacological treatment for OCD. Approximately 40% to 60% of patients treated with SRIs alone will have a response. This is conventionally defined as at least a 25% reduction on the widely used Yale-Brown Obsessive-Compulsive Scale (YBOCS), with an average of 23% to 43% reduction in symptoms (Greist et al., 1995; Pallanti et al., 2002a). Due to the often incomplete reduction of symptoms in patients who respond to SRIs and those patients who do not show a response, additional treatment strategies are often necessary in OCD.
The focus of this review will be primarily on somatic treatments. In this article, treatment-resistant will be defined as less than a 35% reduction of symptoms as measured by the YBOCS after two SRI trials, with or without cognitive-behavioral therapy (CBT) (Pallanti et al., 2002a).
Initial Considerations
An adequate trial of an SRI or clomipramine(Drug information on clomipramine) (Anafranil) consists of at least 12 weeks to reach a full therapeutic dose (Table). If CBT has not already been tried, it should be combined with pharmacotherapy at this point, either by a psychiatrist or by referral to a therapist with experience treating OCD.
