To the Editor: Exposure to a traumatic event and posttraumatic stress disorder (PTSD) are more prevalent among persons with substance use disorders than in the general population (+1). Early diagnosis of this dual problem—PTSD and a substance use disorder—may lead to better treatment outcomes because both conditions can then be treated concurrently (+2). We sought to determine whether the use of a structured psychiatric interview would significantly improve the identification of a history of trauma and the diagnosis of PTSD in a chronically substance-abusing population.

Patients in the study were visitors to a psychiatric emergency department in December 2000. A total of 172 patients who had at least one diagnosis of a substance use disorder were evaluated with the Mini International Neuropsychiatric Interview (MINI) (+3). The mean±SD age of patients in this group was 34.8±10 years. A total of 115 patients (67 percent) were male, and 101 (59 percent) were Caucasian. The control group consisted of 150 patients with at least one diagnosis of a substance use disorder. Their mean age was 37.5±10.8. One hundred of the patients in the control group (67 percent) were male, and 85 (57 percent) were Caucasian. Patients in the control group were randomly selected not to receive a structured interview as part of their clinical evaluation. Patients in both groups had a history of chronic substance abuse or dependence (a mean of 17±4 years of use) and extensive substance abuse treatment (a mean of 3±1 previous treatment episodes). A total of 215 patients (67 percent of the total sample) had at least one co-occurring psychiatric disorder.

Major differences were found between groups in self-reports of traumatic experiences as defined by DSM-IV criteria. Forty-two patients in the group that was evaluated with the MINI reported a significant trauma, compared with 11 patients in the control group (24 percent versus 7 percent; χ²=16.8, df=1, p<.001). Among the patients who reported a traumatic experience, 24 in the study group (57 percent) reported symptoms of PTSD, compared with five in the control group (45 percent). This difference was not significant. A review of the medical records of all patients found only five diagnoses of PTSD on axis I in the study group and three in the control group.

Use of a structured interview in an acute psychiatric setting during the evaluation of patients with substance use disorders led to more frequent identification of a history of trauma and elicited more reports of symptoms related to PTSD. For patients with a substance use disorder, early identification of PTSD may guide the subsequent referral and treatment process (+4). This study supports the use of a structured interview during routine evaluations in this setting. The results of a structured assessment should be considered to be as important as the results of any test, such as an electrocardiogram, a blood test, or the Beck Depression Inventory.

The authors are affiliated with St. Francis Medical Center in Pittsburgh. Dr. Bastiaens is also clinical associate professor of psychiatry at the University of Pittsburgh.