Trauma and PTSD Among Substance-Abusing Patients

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.