A widely prescribed antipsychotic medication worked no better than a placebo to treat combat veterans’ symptoms of post-traumatic stress disorder (PTSD), according to a new study by the Department of Veterans Affairs.
The study, led by Dr. John H. Krystal, director of the clinical neurosciences division of the Veterans Affairs’ National Center for PTSD, involved 247 combat veterans who had PTSD that had failed to respond to at least two antidepressants, the usual treatment for post-traumatic stress. The participants were randomly assigned to begin treatment with placebo or the antipsychotic medication Risperdal (risperidone) — one of a class of drug that was prescribed to nearly 87,000 veterans for PTSD in 2009.
After six months, the researchers found that the veterans taking Risperdal showed no improvement of symptoms over the placebo group: about 5% of participants in both groups responded fully to the drug, while 10% to 20% reported some improvement of symptoms.
There were no significant differences between the groups in scores for depression, anxiety or quality of life. But participants in the Risperdal group were significantly more likely to report side effects like weight gain, fatigue and somnolence than those taking placebo.
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The results surprised the research team. “We fully expected we would find it to be effective on the basis of preliminary studies that found risperidone effective and because it was so widely prescribed,” Krystal told MSNBC.
Instead, the research team said the findings question current prescribing practices for veterans with PTSD. The authors concluded in the paper: “Overall, the data do not provide strong support for the current widespread prescription of risperidone to patients with chronic [antidepressant]-resistant military-related PTSD symptoms, and these findings should stimulate careful review of the benefits of these medications in patients with chronic PTSD.”
The New York Times reported:
The use of such drugs has grown sharply over the past decade, as thousands of returning soldiers and Marines have found that their post-traumatic stress symptoms do not respond to antidepressants, the only drugs backed by scientific evidence for the disorder. Doctors have turned to antipsychotics, which strongly affect mood, to augment treatment, based almost entirely on their experience with them and how they expect them to work.
Though the current study focused only on Risperdal, the results are thought to be applicable to other second-generation antipsychotics in the same class, including Seroquel, Geodon and Abilify.
The study population included recently returning combat veterans from Iraq and Afghanistan, but nearly three-quarters (72.3%) of the patients had military-related PTSD dating back to the Vietnam War. Most also had a history of lifetime major depression (70%) and a history of drug or alcohol abuse (62%).
The study was published Tuesday by the Journal of the American Medical Association.
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Meredith Melnick is a reporter at TIME. Find her on Twitter @MeredithCM. You can also continue the discussion on TIME’s Facebook page and on Twitter @TIME.