The antipsychotic drug risperidone does not improve posttraumatic stress disorder in veterans whose symptoms are resistant to serotonin reuptake inhibitors, according to a report in the Aug. 3 issue of JAMA.
Risperidone was not superior to placebo on any of 10 measures of a spectrum of outcomes in a 6-month study involving 267 military personnel who had experienced combat, said Dr. John H. Krystal of the clinical neurosciences division, Veterans Affairs National Center for PTSD, West Haven, Conn., and his associates.
These findings call into question the widespread off-label use of risperidone and other second-generation antipsychotic drugs for chronic, resistant posttraumatic stress disorder (PTSD). Even though limited evidence supports such therapy and despite "substantial safety concerns," nearly 87,000 veterans diagnosed as having PTSD received an antipsychotic prescription in 2009, and 94% of these prescriptions were for second-generation antipsychotics, the investigators said (JAMA 2011;306:493-502).
Combat-induced PTSD is particularly resistant to pharmacotherapy with serotonin reuptake inhibitors, which have been approved by the Food and Drug Administration for this indication. So it is not surprising that veterans often receive off-label treatment for their intransigent symptoms. Dr. Krystal and his colleagues performed "the first large trial of a pharmacotherapy aimed at SRI-resistant symptoms," enrolling patients who had not responded to or not tolerated at least two adequate (4 weeks or longer) courses of SRIs.
The study subjects were recruited from 23 VA medical centers and randomly assigned in a double-blind fashion to receive risperidone (133 patients) or an identical-looking placebo (134 patients), in addition to their regular PTSD treatments. The subjects underwent extensive assessment – with 10 different instruments measuring PTSD symptoms, global clinical factors, quality of life, sleep quality, depression, anxiety, and psychosis – at baseline, 6 weeks, 12 weeks, and at the conclusion of the intervention at 24 weeks.
These patients were severely ill, with disabilities related to long-standing PTSD. Most (72%) had served in the Vietnam War or earlier conflicts, though 24% had seen action in the Iraq or Afghanistan wars. The mean subject age was 54 years, and 97% were men. Approximately 70% of the study subjects also met the criteria for major depression, and 63% met the criteria for alcohol abuse or dependence.
The primary outcome measure was the score on the 34-item Clinician-Administered PTSD Scale (CAPS). These scores decreased slightly over time with both risperidone (mean decrease, 16.3 points) and placebo (mean decrease, 12.5 points), and the difference between the two groups was not significant.
Moreover, the rate of remission did not differ between patients taking risperidone (4%) and those taking placebo (5%), Dr. Krystal and his colleagues reported.
The two groups also had similar outcomes on the Clinical Global Impression Scale, the Montgomery-Åsberg Depression Rating Scale, the Hamilton Anxiety Scale, the Positive and Negative Syndrome Scale, the Veterans RAND 36-Item Health Survey, the Boston Life Satisfaction Inventory, and all other measures.
Although risperidone was numerically superior to placebo on submeasures of hyperarousal and "re-experiencing," the effect was so small that it likely would not even be detected clinically, the researchers said.
Patients who took risperidone reported significantly more problems with weight gain, fatigue, somnolence, and hypersalivation. However, risperidone exerted no significant effects on three measures of extrapyramidal symptoms.
This study was supported by the VA Office of Research and Development. Risperidone and matching placebo were donated by Ortho-McNeil Janssen Scientific Affairs. Dr. Krystal reported ties to numerous industry sources, as did his associates.