According to a study of JAMA, (August 3 theme issue on violence and human rights) patients who suffered from military-related, chronic posttraumatic stress disorder (PTSD) who did not respond properly to antidepressant medication, did not experience a decrease in PTSD symptoms by using antipsychotic medication risperidone.

The most common and disabling psychiatric disorder for military personnel serving in combat is PTSD. The most frequently used pharmacotherapy for PTSD are antidepressants. Background information of the article reveal that the U.S. Department of Veterans Affairs (VA) treats 89% of its PTSD diagnosed veterans with therapy and prescribed serotonin reuptake inhibitors (SRIs).

According to the authors:

“SRIs appear to be less effective in males than in females and less effective in chronic PTSD than in acute PTSD. Therefore, it may not be surprising that an SRI study in veterans produced negative results. Second-generation antipsychotics (SGAs) are widely used medications for SRI-resistant PTSD symptoms, despite limited evidence supporting this practice.”

John H. Krystal, M.D., of the VA Connecticut Healthcare System, West Haven, Conn., and team researched whether risperidone (a second-generation antipsychotic widely used for schizophrenia and bipolar disorder) in addition to a continuing pharmacotherapy would be more effective than a placebo to decrease chronic military-related PTSD symptoms amongst veterans whose symptoms did not alter after at least 2 adequate SRI treatments.

The study was undertaken over a 6 month period – it was a randomized, placebo-controlled multicenter trial between February 2007 and February 2010 at 23 Veterans Administration outpatient medical centers. 296 of the 367 screened patients were diagnosed with military-related PTSD showing ongoing symptoms despite at least 2 satisfactory SRI treatments with 247 patients contributing to the analysis of the primary outcome measure. Patients were administered to receive either a once-daily dose of up to 4mg of risperidone or a placebo, and other psychosocial mental health therapies. Symptoms of PTSD, depression, anxiety and other health outcomes were determined via various scales and surveys.

The analysis of the data revealed to researchers that there was no statistically significant difference after 6 months of treatment between risperidone and placebo in reducing PTSD symptoms. Additionally, risperidone did not prove to be statistically superior to placebo on any of the other outcomes, including improvement on life quality measures, depression, anxiety or paranoia/psychosis. In general, the rate of adverse events during treatment was low but did not seem related to the dosing of risperidone.

The authors concluded: