Pharmacological augmentation strategies for treatment-resistant obsessive-compulsive disorder.

First-line treatment for obsessive-compulsive disorder (OCD) has been well-established for over a decade, although newer medications, such as citalopram and venlafaxine, have emerged to take a place among the older, more established serotonin re-uptake inhibitors (SRIs). Unfortunately, as many as 50% of all patients with OCD will have symptoms refractory to a single medication treatment trial, and a smaller percentage will remain refractory after two or more trials. The optimal dosage and duration for first-line trials have been established. Many strategies exist for patients who do not respond to first- or second-line medication trials, including behavioural therapy, switching to newer SRIs, and augmentation with additional medications. This review will focus on medication strategies for augmenting SRI treatment response in OCD treatment, including neuroleptic and serotonergic agents. Future investigations should include more controlled studies and investigate medications that are less likely to trigger extrapyramidal symptoms, diabetes mellitus and weight gain.