WEST HAVEN—Patients with combat-related PTSD did not respond to risperidone (Risperdal), according to the results of a multicenter VA study.

Risperdal, an antipsychotic, has been found successful in treating schizophrenia, bipolar disorder, and some of the symptoms of autistic disorder. The drug acts primarily on the dopaminergic and serotonergic systems.

Physicians have been using risperidone and other second-generation antipsychotics as adjunctive therapy for PTSD patients who do not respond to selective serotonin reuptake inhibitors (Saris) believing that it could improve the hyperarousal and re-experiencing symptoms of PTSD. In 2009, nearly 87,000 veterans with PTSD were treated with an antipsychotic.

However, a study published in the August 3 issue of the Journal of the American Medical Association showed that patients treated with Risperdal had no statistically significant improvement compared to those treated with placebo. The research team, based out of the VA Connecticut Healthcare System in West Haven, looked at 267 PTSD patients spread across 23 VA facilities. The patients all had Clinician-Administered PTSD Scale (CAPS) scores of greater than 50, had failed to respond to at least two antidepressants and were not responding to SSRI treatments.

The patients were randomized for either risperidone or placebo for six months. Researches then examined the patients’ CAPS score. The results should a CAPS score decline of 16.3 points in the risperidone group and 12.5 points in the placebo group. The difference of four points was not statistically significant, the researchers said in their report.

Looking at secondary outcomes, such as anxiety levels and quality of life, they found no significant difference between the two groups. The biggest difference between the two groups was in adverse events, with weight gain, fatigue, somnolence, and hypersalivation occurring at a much greater frequency in the risperidone arm.