Treatment of Posttraumatic Stress Disorder: An Assessment of the Evidence

 

Institute of Medicine

 

Telephone News Conference

October 18, 2007

 

Opening Statement by

 

Alfred O. Berg

Professor, Department of Family Medicine, University of Washington School of Medicine

And Chair, Committee on Treatment of Posttraumatic Stress Disorder

 

Good morning.  Thank you for joining us for the release of our report to the Department of Veterans Affairs on the treatment of posttraumatic stress disorder.  Joining me today is fellow committee member David Matchar.

 

At the request of the VA, the Institute of Medicine convened our committee to reach evidence-based conclusions about the efficacy of various PTSD treatments.  In this statement, I will summarize our conclusions and recommendations, and highlight the report's three key messages.  The VA also asked the committee to comment on several important related matters, including recovery from PTSD, length of treatment, and early intervention.

 

Over a nine-month period, the committee engaged in the challenging task of reviewing and assessing the published, peer-reviewed research studies on PTSD treatment.  We identified 90 studies that met our criteria, were relevant, and that we anticipated would provide useful information.  Based on our assessment of these studies, we reached the following conclusions:

 

 

 

 

Let me speak briefly about how the committee reached its conclusions about the evidence base.  We assessed the quality of each study and identified any limitations that could skew a study's results.  Several studies had problems with a high proportion of participants discontinuing treatment before the end of the study, which led to incomplete data.  Some of the statistical analyses used to address this problem were inappropriate and weakened the study's results.  In other cases, the researchers were not "blind" -- that is, they were aware to which therapies participants were assigned.  Lack of blinding can lead to bias.  And in some cases, key information, such as how many participants completed the study, was not reported.  The issue of poor handling of missing data emerged as a fairly widespread limitation in these studies, and we discussed this issue in detail in Chapter 5 and in Appendix D.  The committee made its judgments about each treatment based on the quality of the cumulative body of evidence for that treatment.  We also considered the impact of further research and likelihood that future high-quality studies would continue to show that the therapy has an effect.

 

Based on this review, our first key message is that most pharmaceuticals and psychotherapies may or may not be effective in helping patients with PTSD; in most cases, we just don't know because of the absence of good data.

 

Our second key message is that many of the studies that have looked into the effectiveness of PTSD therapies have limitations and therefore do not provide a clear picture of what works and what doesn't.

 

As outlined in our methods and in an appendix, we found much of the research on PTSD to have major limitations when judged against contemporary standards for conducting randomized, controlled trials.  Authorities in the field of PTSD research have called for more attention to improving the quality of research methods.  Although we recognize that PTSD research perhaps presents special challenges, we know that high-quality studies are possible because we found some examples in our search of past studies.  We recommend that the agencies and organizations that fund PTSD research take steps to ensure that investigators improve the internal validity of research in this field.

 

The majority of drug studies have been funded by the pharmaceutical manufacturers, and the majority of psychotherapy studies have been conducted by the individuals who developed the techniques or their close collaborators.  We recommend that a broader range of investigators be supported to conduct studies that would replicate and confirm the earlier studies.

 

We recommend that researchers identify important subpopulations and conduct studies of PTSD interventions tailored to their specific needs.  These subpopulations include people with concurrent disorders such as substance abuse, ethnic minorities, and veterans with traumatic brain injury.

 

The committee found that research on veterans with PTSD is inadequate to answer VA's questions about interventions, settings, and length of treatment.  We recommend that Congress require and ensure that resources are available to fund quality research on the treatment of veterans with PTSD.  We also recommend longer-term follow-up studies after treatment concludes.

 

The committee also found that the available research has not systematically addressed needs of veterans, and there are apparent discrepancies between the chosen topics for study and actual practice.  We recommend that the VA take an active leadership role in identifying research priorities for addressing gaps in evidence in clinical efficacy and comparative effectiveness.

 

This leads to our third key message -- that given the growing number of veterans with PTSD and the seriousness of this disorder, the VA, Congress, and the research community urgently need to take steps to ensure that the right studies are undertaken to yield clearer, more reliable data that would help clinicians treat PTSD sufferers.

 

In summary, the committee describes the evidence supporting treatments for PTSD, and offers a number of recommendations for future research.  PTSD is a relatively newly recognized disorder and research on treatments is still in the early stages.  Not only veterans, but millions who have been exposed to trauma suffer from PTSD.  Research on this disorder should be a high priority, and VA should take the lead to ensure that the specific needs of veterans are addressed adequately.

 

The committee is grateful to have the opportunity to be of assistance to VA, and hopes that the department finds the report useful as it continues to care for veterans with PTSD.  This concludes my opening remarks.  My colleague Dr. Matchar and I will be happy to take your questions now.  Thank you.