inclusion criteria. The committee also notes that there may be a need for the development and evaluation of efficient adaptations of standard psychotherapies for PTSD, such as prolonged exposure. A course of treatment, delivered in a shorter period of time (less than the typical 10–12 weeks), in more frequent and fewer sessions, might have the added benefit of increasing the rate of treatment completion.

Finding 8. The evidence base contained studies that varied greatly on length of treatment and other variables, therefore, the committee was unable to draw conclusions regarding optimal length of treatment with psychopharmacology or psychotherapy.


Recommendation 8. The committee recommends that VA and other funders call for research on the optimal duration of various treatments. Trials of comparative effectiveness of different treatment lengths for those treatments found efficacious should follow. Finally, studies with adequate long-term (i.e., greater than 1 year) follow-up should be conducted on treatments of any length found to be efficacious.

Length of Follow-Up

Ideally, improvements during treatment endure long after treatment is complete. Evaluation of treatment effectiveness should include follow-up over a sufficient period to determine whether improvement is maintained, continued, or declines. Treatments for which improvements are not maintained provide short-term relief but may have long-term consequences as symptoms recur. Patients may be reluctant to try again, or may remain dependent on the treatment, which may be impractical or costly. When improvement is maintained or continues after treatment concludes, one can infer that these patients have acquired permanent positive changes that enable them to function more effectively or comfortably independent of treatment.

The literature examined by the committee was limited in providing long-term follow-up. The committee understands that follow-up beyond treatment is uncommon in drug studies aimed at addressing efficacy, regardless of clinical condition, but nonetheless observed that only 11 of 36 drug studies followed patients beyond treatment cessation, and none longer than 6 months. Thus, in general, the committee could not address what occurs when medications are discontinued. The evidence on longer-term follow-up is somewhat more extensive for psychotherapy. Of 52 psychotherapy studies, 43 reported follow-up data: 14 for 3 months or less, 18 for 6 to 9 months, 6 for 12 months, and 5 for 15 or more months. The evidence becomes scant, however, for effectiveness beyond 15 months, with the



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement