This study will examine the efficacy of pregabalin (Lyrica) added to serotonin-reuptake inhibitor (SRI) treatment in obsessive-compulsive disorder (OCD) for individuals who have not responded or only partially responded to an adequate trial of an SRI. Although SRIs have demonstrated efficacy in OCD in numerous placebo-controlled trials, response rates have been as low as 40%. Augmentation strategies (adding an another medication) would be beneficial to maximize treatment response in OCD. The study will consist of patients who have not attained full response to an SRI. The patients will be randomized in a double-blind fashion to the addition of pregabalin (Lyrica) or placebo to the regular dose of SRI. At the end of the study, particpants will enter follow-up care with the study doctor.

McMaster University Medical Centre
Principal Investigator
Michael Van Ameringen, MD
Eligibility Criteria
  • Male or female outpatients 18 years or older with a primary diagnosis of obsessive compulsive disorder, who are currently being treated with an SRI (eg. paroxetine, fluoxetine, fluvoxamine, clomipramine, sertraline, citalopram, escitalopram) or SNRI (venlafaxine, desvenlafaxine, duloxetine) and continue to have OCD symptoms.
  • Physical examination, electrocardiogram, and laboratory findings without clinically significant abnormalities.
  • Willingness and ability to comply with the requirements of the study protocol.
  • Those taking psychotrophic medications, other than an SRI/SNRI are excluded.
The MacAnxiety Research Centre, 905-921-7644 or e-mail
Hamilton, ON