A Systematic Review of Evidence-based Treatment Strategies for Obsessive- compulsive Disorder Resistant to first-line Pharmacotherapy.

Abstract

Serotonin reuptake inhibitors (SRIs) and cognitive-behavioral psychotherapy (CBT) are first-line treatments for obsessive-compulsive disorder (OCD). However, a significant proportion of patients do not respond satisfactorily to first-choice treatments. Several options have been investigated for the management of resistant patients. The aim of the present paper is to systematically review the available literature concerning the strategies for the treatment of resistant adult patients with OCD. We first reviewed studies concerning the definition of treatment-resistant OCD; we then analyzed results of studies evaluating several different strategies in resistant patients. We limited our review to double-blind, placebo-controlled studies performed in adult patients with OCD whose resistance to a first adequate (in terms of duration and dosage) SRI trial was documented and where outcome was clearly defined in terms of decrease in Yale-Brown Obsessive-Compulsive Scale (YBOCS) scores and/or response/ remission rates (according to the YBOCS). We identified five strategies supported by positive results in placebo-controlled randomized studies: 1) antipsychotic addition to SRIs (16 RCTs, of them 10 positive; 4 head-to-head RCTs); among antipsychotics, available RCTs examined the addition of haloperidol (butyrophenone), pimozide (diphenyl-butylpiperidine), risperidone (SDA: serotonin- dopamine antagonist), paliperidone (SDA), olanzapine (MARTA: multi-acting receptor targeted antipsychotic), quetiapine (MARTA) and aripiprazole (partial dopamine agonist); 2) CBT addition to medication (2 positive RCTs); 3) switch to intravenous clomipramine (SRI) administration (2 positive RCTs); 4) switch to paroxetine (SSRI: selective serotonin reuptake inhibitor) or venlafaxine (SNRI: serotonin-norepinephrine reuptake inhibitor) when the first trial was negative (1 positive RCT); and 5) the addition of medications other than an antipsychotic to SRIs (18 RCTs performed with several different compounds, with only 4 positive studies). Treatment-resistant OCD remains a significant challenge to psychiatrists. To date, the most effective strategy is the addition of antipsychotics (aripiprazole and risperidone) to SRIs; another effective strategy is CBT addition to medications. Other strategies, such as the switch to another first-line treatment or the switch to intravenous administration are promising but need further confirmation in double-blind studies. The addition of medications other than antipsychotics remains to be studied, as several negative studies exist and positive ones need confirmation (only 1 positive study).