Half a dozen studies have found that the drug prazosin, used to treat high blood pressure and several other conditions, helps with nightmares and other symptoms in people with post-traumatic stress disorder (PTSD). So researchers were surprised when a new, larger study, reported last year in The New England Journal of Medicine, did not confirm this effect.
For the New England Journal study, researchers randomly assigned 304 military veterans (average age, 52) who had PTSD and frequent nightmares to receive prazosin or a placebo for 26 weeks. When it came to frequency and intensity of nightmares, sleep quality, and general sense of well-being, participants who took prazosin did no better than those who took a placebo. The findings were the same in both the short term (10 weeks) and the long term (26 weeks).
Unlike in some of the previous studies, people were not allowed to enroll in this study if their PTSD was unstable or they were experiencing a life crisis. The authors said it is possible that prazosin is more likely to work in such less-stable individuals, which could explain the discrepancy from previous trials.