Study Questions Criteria for Diagnosing PTSD
Harvard-affiliated McLean Hospital Researchers Call for Evaluation of Post-Traumatic Stress Disorder criteria
FOR IMMEDIATE RELEASE:
March 21, 2007
Belmont, MA - A study by researchers at Harvard-affiliated McLean Hospital has found that the symptoms used to diagnose post-traumatic stress disorder (PTSD) are common among patients seeking treatment of depression, whether or not they have a history of trauma. The finding raises serious questions about the validity of the set of symptoms currently used to diagnose PTSD
In a paper published in the March 21 issue of the Journal of Anxiety Disorders (abstract) , the team headed by J. Alexander Bodkin, MD, director of the Clinical Psychopharmacology Research Program at McLean Hospital, found that the symptoms used to diagnose PTSD are found equally often in depressed patients who have never experienced a major trauma.
"Our findings, along with others previously reported, form a growing body of literature that raises the important question of whether the symptoms of PTSD are necessarily caused by trauma,'' said Bodkin. "Instead, it appears that the symptoms currently attributed to PTSD may be a non-specific group of symptoms widely observed in patients with mood and anxiety disorders, regardless of trauma history. As a result, caution should be exercised in attributing the PTSD syndrome to trauma.''
In the study, the researchers questioned 103 patients presenting for treatment of major depression about whether they had suffered traumatic experiences, and examined them for symptoms of PTSD.
Of 54 patients who were deemed to have experienced a major trauma (as determined by independent raters blinded to those patients' symptoms), 78 percent met the American Psychiatric Association's symptom criteria for PTSD as defined by the Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV). These include such symptoms as intrusive thoughts, emotional numbing, flashbacks, difficulty sleeping, jumpiness and hopelessness, among others.
But of 36 subjects who were found by raters not to have experienced major trauma, 78 percent still met the manual's symptom criteria for PTSD.
And of 11 patients whom the researchers could not be certain met the criteria for having experienced a traumatic event, 85 percent also met the symptom definition for PTSD.
Bodkin said the findings suggest that the symptom criteria being used to diagnose a patient with PTSD is not specific to people who have been traumatized. He suggested that the criteria might need to be revised. If not, the diagnosis may be misleading and as a result, patients may not be getting the treatment they need, he said.
"In order to save the diagnosis, we need to sharpen and refine the symptoms we attribute to PTSD,'' said Bodkin, an assistant professor of psychiatry at Harvard Medical School.
According to the National Institute of Mental Health (NIMH), PTSD develops after a terrifying ordeal that involves physical harm or the threat of physical harm. Symptoms usually begin within three months of the incident but occasionally emerge years afterward. They must last more than a month to be considered PTSD. In some people, the condition, which affects some 7.7 million American Adults, becomes chronic.
The diagnosis was first recognized by the psychiatric community in 1980, following the Vietnam War, after veterans returned home exhibiting symptoms formerly known as "shellshock.'' Since then, the diagnosis has been widely applied to those victimized by a variety of other traumas, including rape and child abuse, as well as much milder traumatic life events.
Bodkin noted that many of the symptoms listed by DSM-IV, as included in the diagnostic criteria for PTSD, are also included in the criteria for a variety of other disorders, including major depressive disorder, generalized anxiety disorder and others. This fact led to the design of the study, which sought to test whether the clinical syndrome of PTSD requires prior exposure to trauma or whether the same symptom picture can occur in the absence of trauma.
Because the study showed that symptoms diagnostic of PTSD were seen at the same rates in depressed patients regardless of trauma, the authors said that it might be incorrect to assume that the symptoms found in those who had experienced trauma were actually caused by trauma.
"This finding is important because therapy is structured, research studies designed and legal compensation awarded on the basis of the assumption that PTSD symptoms are caused by exposure to trauma," explained Bodkin. "The findings suggest that the diagnosis of PTSD may frequently be given to patients in whom psychological trauma had little or no causal role in their psychiatric illness. This would mean that the PTSD diagnosis may be given too frequently and that the condition may be less common than widely believed."
Bodkin added that many mental health professionals "reason backwards" in making a PTSD diagnosis, meaning they identify a patient's symptoms as typical of PTSD and then probe to find out what the patient's trauma had been. This would further increase the risk of falsely attributing mental illness to traumatic life events.
The study's findings "question whether under the current criteria it is ever appropriate to reason backwards from the symptoms,'' he said.
Bodkin said the findings also help explain why many studies have differed in estimating the rate of PTSD in the population. "It is a difficult diagnosis to make,'' he said.U.S. News & World Report consistently ranks McLean Hospital the nation's top psychiatric hospital. McLean is an affiliate of Harvard Medical School and Massachusetts General Hospital, and a member of Partners HealthCare.