If you were experiencing flashbacks and severe anxiety, wouldn't you prefer a treatment that worked in two weeks rather than eight weeks if both were equally effective? People with post-traumatic stress disorder (PTSD) may soon have that choice, based on the results of a five-year study that found that the relief provided by just two weeks of prolonged exposure therapy (PE) was as good as the same therapy parceled out over eight weeks. Both treatments consisted of 10 therapy sessions.

Prolonged exposure therapy asks people with PTSD to confront their traumatic experiences not avoid them. There had been concern that the 10 longer, daily PE sessions would be too emotionally taxing for patients. That proved not to be true in this study.

Traumatic experiences leave a long shadow, but why take eight weeks of therapy if two weeks will work just as well?

Over 350 active-duty military personnel who had been diagnosed with PTSD took part in the study. The participants were divided into three groups: 110 received the two-week PE treatment; 110 received the eight-week PE treatment; 110 received eight weeks of a different treatment called Present-Centered Therapy (PCT), which does not rely on having people confront their traumatic experiences, but instead focuses on the present, particularly on daily stresses; finally, 40 received four 10-15 minute weekly telephone calls from therapists. This last group acted as controls.

The severity of each soldier's PTSD was measured before treatment and at two weeks, 12 weeks and six months after treatment.

Two-week PE treatment was found to be as effective at reducing the severity of PTSD symptoms as the eight-week course. Interestingly, Present-Centered Therapy treatment showed the same degree of effectiveness, suggesting that PTSD treatment does not have to be one-size fits all and offering an alternative for people who do not respond well to PE treatment.

Unfortunately, the treatments were hardly a cure. As an editorial accompanying the study points out, six months after treatment, over 60 percent of the PE- and PCT-treated people still met the criteria for a diagnosis of PTSD. While any relief of symptoms is likely welcome, the study underscores a continuing need for more effective treatments. Traumatic experiences leave a long shadow, but why take eight weeks of therapy if two weeks will work just as well?

All the participants in this study were military personnel, but there's no reason to expect that its results won't also hold true for victims of sexual assault and other types of abuse, accidents or disasters.

The study appears in JAMA and is freely available.