DSM-IV criteria for posttraumatic stress disorder (PTSD) are
well-founded and should remain the standard for diagnosis, the Institute of
Medicine (IOM) reported in June. The report had been requested by the
Department of Veterans affairs in response to concern about increasing numbers
of veterans applying for PTSD disability compensation.
Diagnosis should be carried out by experienced clinicians familiar with
DSM-IV standards, added the IOM group, chaired by Richard Mayeux,
M.D., M.S., a professor of neurology, psychiatry, and epidemiology at the
College of Physicians and Surgeons at Columbia University.
"The committee strongly concludes that the best way to determine
whether a person is suffering from PTSD is with a thorough, face-to-face
interview by a health professional trained in diagnosing psychiatric
disorders," Mayeux said.
"In asking the IOM to evaluate and confirm the DSM-IV
criteria, the VA was not seeking to challenge the criteria but to provide
validation of those criteria to those who did challenge them," said Ira
Katz, M.D., Ph.D., deputy chief patient care services officer for mental
health at the VA. "The goals were very well met."
Acceptance of the DSM-IV criteria meant that new, idiosyncratic
standards need not be created and verified, a major concern for Darrel Regier,
M.D., M.P.H., executive director of the American Psychiatric Institute for
Research and Education and director of APA's Division of Research.
"Frankly, I'm surprised that things went so smoothly," Regier
told Psychiatric News. "A panel of experts agreed that the
present criteria were evidence based and that there were plenty of assessment
instruments to use."
Separating diagnosis from treatment and disability was a good choice
because the latter two issues probably lay more at the heart of the VA's
concerns, said Regier.
The IOM committee will also review evidence for PTSD treatment and
prognosis and for determining standards of disability related to the disorder.
Those two reports are expected by the end of the year.
Although the primary diagnostic tool for PTSD is the knowledge and
experience of the clinician, the report also suggested that use of structured
or semistructured interviews such as the Clinician-Administered PTSD Scale
(CAPS), the Structured Clinical Interview for DSM-IV (SCID), the PTSD
Symptom Scale—Interview Version (PSS-I), can complement clinical
interviews.
While some of these interviews might take time to administer, they can
provide indications of presence and severity of symptoms.
"If you're making judgments with major treatment and compensation
implications, time shouldn't be an issue," said Regier.
Self-report instruments of war-related stress may help the clinician elicit
greater detail about trauma exposure than an initial interview would, said the
report, but "they should not substitute for a comprehensive diagnostic
interview."
The VA uses the same four-question screening test for PTSD as the
Department of Defense. It also uses a number of other instruments to evaluate
symptoms and treatment response but has no system-wide convention for choosing
them.
No biomarkers currently have sufficient sensitivity and specificity to be
useful for diagnosing PTSD, noted the IOM committee, in response to a question
from the VA. Neuropsychiatric tests might help validate subjective reports,
but they were less useful diagnostically because results might characterize
other psychiatric disorders as well.
The IOM also noted that PTSD was a true disorder because it met standards
for validity, having distinct clinical features that had been consistently
documented in a variety of settings and cultures, longitudinal stability, and
some evidence that genetic factors accounted for about one-third of PTSD
symptoms.
At committee hearings in February, several speakers suggested that many
veterans applying for disability compensation for PTSD through the VA were not
suffering from the disorder, but looking for a government pension. clinicians
should be aware of the potential for malingering and should consider
discrepancies in the patient's reports, lack of cooperation in evaluation or
treatment, and evidence of antisocial personality disorder in their
evaluation, said the committee, echoing APA recommendations.
"Part of the reason for asking that clinically well-trained people
evaluate patients is to avoid overdiagnosing people faking PTSD," said
Regier. Several psychometric tests, like the MMPI-2 or the Impact of Event
Scale—Revised, do a good job of detecting fakery, he added. Other
speakers at the February hearings presented evidence that there were few
instances of malingering among Vietnam War veterans studied. although the
impetus for the IOM report arose from concern about veterans of earlier wars,
Katz said that about 30 percent of returning veterans of Iraq and Afghanistan
come to the VA for medical care. Of those, 33 percent have mental health
concerns, and 15 percent of that group have at least some symptoms of
PTSD.
Nothing specific in the report should cause the VA to change its approach
to diagnosing PTSD, but the department is continually seeking to improve its
services, said Katz. "The issue isn't business as usual, but enhancement
as usual," he said. "The VA views the best diagnosis as an
evolving process, guided by empirical-research evidence and accumulating
evidence."
The IOM report also did not presage any developments for PTSD criteria that
might appear in DSM-V, said Regier. Research over the next several
years may generate new information that could confirm present standards or
guide new ones, he said.
"Posttraumatic Stress Disorder: Diagnosis and
Assessment" is posted at<www.nap.edu/catalog/11674.html#toc>.▪