There are a number of treatments for post-traumatic stress disorder or PTSD, and it hasn't been clear which works better. Part of the problem, a study finds, is that the treatment that works best is the one a PTSD patient chooses.

The trial, comparing the effectiveness of behavioral therapy and medication to relieve the flashbacks and other symptoms of PTSD, found that when people were able to choose their own therapy, they did better, regardless of which treatment they chose.

While many people associate PTSD with combat, more than half the people in the study received their PTSD diagnosis due to a sexual assault in either childhood or adulthood.

Of the PTSD patients who were allowed to choose their preferred treatment, nearly three-quarters stuck with it to the end. On the other hand, over half of the patients who were assigned to treatment did not complete their 10-week course. Even more importantly, people who received the treatment they preferred were much more likely to be essentially PTSD-free two years after the trial began. Just from a little over two months of treatment.

It appears people know their own minds better than their doctors do .

In the study, patients were asked to express a preference for either 10 weeks of prolonged exposure therapy, a behavioral treatment in which a person is gradually exposed to what they fear, learning to become less fearful of it over time; or 10 weeks taking the antidepressant medication Sertraline (Zoloft). Half were given the treatment of their choice; the other half were randomly assigned one of the two treatments.

Both treatments proved effective, with exposure therapy performing a bit better. But the biggest difference came from whether or not people chose their own therapy: When people who preferred exposure therapy received it, 74 percent were no longer diagnosed as having PTSD diagnosis two years later. But when they received medication instead, only 37 percent were free of PTSD symptoms after two years.

People do have a choice, as co-author, Norah Feeny, a professor of psychology at Case Western Reserve University, points out, there are two effective, very different interventions for chronic PTSD; using the treatment the patient prefers is likely to make whichever treatment is chosen that much more effective.

In general, patients were more likely to show a preference for exposure therapy (61 percent). Exposure therapy encourages people to talk about what happened to them, learn coping strategies and come to terms with their thoughts and feelings by repeatedly approaching their memories of their trauma memories and the reminders that trigger them.

While many people associate PTSD with combat, more than half the people in the study received their PTSD diagnosis due to a sexual assault in either childhood or adulthood. Lead author, Lori Zoellner, a professor of psychology at the University of Washington and director of the University's Center for Anxiety & Traumatic Stress, offers some straighforward advice: “ Survivors should know good, short options exist and need not suffer in silence.”

The study appears in the American Journal of Psychiatry .