Although selective serotonin reuptake inhibitors (SSRIs) are a treatment for OCD, research at the time of this study showed that 40-50% of OCD patients experienced small or no symptom reduction after using them.

A pilot study led by Dr. Shapira showed that tramadol hydrochloride (an opioid pain reliever) could help with treatment-resistant OCD, as tramadol binds to opioid receptors and inhibits norepinephrine and serotonin. Tramadol also has a low potential for abuse, mild tolerance, and low dependency. This double-blind study sought to serve as a continuation of the pilot study, and placed 30 patients with OCD into two groups for 10 weeks — one receiving tramadol and the other receiving a placebo.