Most PTSD therapies not supported by evidence.

Evidence is insufficient to support most of the therapies and medications now in use for posttraumatic stress disorder, concludes an Institute of Medicine panel report issued in October after 9 months of investigation.

"This result was unexpected and may surprise [Veterans Affairs] and others interested in this disorder," the committee wrote in the preface to its report, "Treatment of Posttraumatic Stress Disorder: An Assessment of the Evidence."

Among the therapies found to be lacking evidence of effectiveness: cognitive restructuring, coping-skills training, individual psychotherapy, and group therapy, the panel said. In addition, not a single drug therapy has sufficient evidence to say that it has utility in treating PTSD, said panel chairman Dr. Alfred O. Berg, professor of family medicine at the University of Washington, Seattle, in a telebriefing with reporters.

Only exposure therapy--in which the patient is exposed to a real or surrogate threat in a safe environment--had enough evidence to warrant a conclusion that it is effective, the panel said.

Dr. Berg pointed out that the aim of the report is to spur more sophisticated research into PTSD's causes, diagnosis, and treatment. It is not meant to provide guidelines for clinicians.

"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," Dr. Berg said.

The panel was not in consensus on all the recommendations. Only two of the eight members of the committee were psychiatrists, and one--Dr. Thomas A. Mellman of Howard University, Washington--disagreed with the committee's conclusions that selective serotonin reuptake inhibitors were not useful in the general PTSD population and that newer-generation antipsychotics might not be effective.

The Department of Veterans Affairs (VA) requested the IOM study, but its findings have much broader implications, said Dr. Berg, noting that PTSD affects some 12-20 million Americans, only several hundred thousand of whom are veterans.

Dr. Berg estimated a lifetime prevalence of 7% in the U.S. population and a current prevalence of 3.6%. In addition, data indicate that 13% of those who have served in Iraq and 6% of those who have served in Afghanistan have experienced PTSD.

"Those are very large numbers," Dr. Berg said.

Only 90 studies met the committee's criteria for inclusion in its review of the available data. The vast majority--53--were of pharmaceuticals. There were 37 psychotherapy studies. Many studies had high dropout rates, from 20% to 50%, and statistical analyses used to adjust for that factor weakened results, he said. Studies also had lack of blinding or missing data.

Finally, most of the drug studies were funded by the manufacturers, and most psychotherapies were investigated by their inventors or close collaborators, the panel noted.

The IOM committee urged replication of these trials by a broader range of investigators.

Exposure therapy had the strongest evidence supporting its use. The panel reviewed 24 randomized, controlled trials of exposure therapy, some of which had cognitive restructuring or coping skills added as adjunctive therapies.

The evidence also did not address in any way the effects of comorbidities in veterans, including major depression, traumatic brain injury, and substance abuse. So the panel's conclusions might not apply to "the substantial proportion of veterans with one or more important comorbidities," the report said.

"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," Dr. Berg said.

The IOM panel recommended that the Department of Veterans Affairs and other organizations that fund research help identify methods to improve the internal validity of research, to encourage broader investigations into more subgroups of veterans, and to find ways to fund comparative effectiveness research.

There should also be longer follow-up in trials, said the panel, noting that no good data exist on the optimal duration of drug or psychotherapy treatment.

One of the report's reviewers, Dr. Arthur S. Blank Jr., agreed that higher-quality trials of PTSD interventions are needed. But he differed on how those trials should be carried out.

For one thing, those studies should be more naturalistic, said Dr. Blank, who served as an Army psychiatrist in Vietnam and as the national director of war veterans counseling centers at the VA headquarters. Most PTSD patients are receiving multiple interventions simultaneously, he said. Studies should be conducted to examine therapies in the way they are administered, said Dr. Blank, of the department of psychiatry at George Washington University, Washington.

He also criticized the committee's approach to reviewing the evidence. The panel gave the most credence to randomized, controlled trials, and those studies "are of limited usefulness in evaluating the usefulness of psychiatric conditions," Dr. Blank said in an interview.

Randomized, controlled trials cannot truly document the effectiveness of interpersonal psychotherapy, for instance. "We know what works to a considerable degree," he said, adding that clinicians are building on 30 years of experience treating PTSD in veterans.

BY ALICIA AULT

Associate Editor, Practice Trends