Selective serotonin re-uptake inhibitors (SSRIs) versus placebo for obsessive compulsive disorder

Feb 20 2008

Common antidepressant drugs such as Prozac and Zoloft can be effective treatment options for obsessive compulsive disorder (OCD), according to a new review of studies.

Patients who take selective serotonin reuptake inhibitors, or SSRIs, are twice as likely to get some relief from their OCD symptoms as those who take placebo pills are.

However, the drugs have a “modest” effect at best, said Dr. Ghulam Mustafa Soomro, lead review author and honorary research fellow at St. George's Hospital Medical School in London.

“Although SSRIs should be considered potentially effective treatments for OCD patients, treatment decisions need to take account of the potential adverse effects of these drugs,” including nausea, insomnia and sexual dysfunction, he warned.

The review of studies appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews like this one draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

Many people with OCD seek out therapy that teaches them to confront, tolerate and gradually wean themselves from obsessive and compulsive behaviors.

“This is the primary kind of therapy used for OCD. It teaches patients to pay attention to their internal experiences and tolerate scary thoughts without having to act on them,” said Sanjaya Saxena, M.D., director of the Obsessive-Compulsive Disorders Program at the University of California, San Diego School of Medicine. “They learn that nothing terrible happens if they refrain from their usual compulsive behaviors.”

Nevertheless the success rates for this type of therapy vary, and “unfortunately, about 25 percent of patients offered this form of treatment refuse it,” Soomro said, adding that SSRIs “may offer help to some of these patients.”

After reviewing 17 studies that included 3,097 patients, the reviewers concluded that SSRIs were more effective than a placebo in reducing OCD symptoms six to 13 weeks after starting treatment.

None of the drugs stood out above the rest; they all appeared equally effective. However, in most cases, side effects such as nausea and headache were noticeably worse with the SSRIs than with the placebo pills.

The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.

Soomro GM, et al. Selective serotonin re-uptake inhibitors (SSRIs) versus placebo for obsessive compulsive disorder (OCD) (Review). The Cochrane Database of Systematic Reviews 2008, Issue 1.