Empirical development of an MMPI subscale for the assessment of combat-related posttraumatic stress disorder.

Abstract

Few guidelines exist for the psychological assessment of posttraumatic stress disorder (PTSD) in Vietnam combat veterans. The focus of the present study was to develop empirically based criteria for use of the Minnesota Multiphasic Personality Inventory (MMPI) to aid in the assessment and diagnosis of PTSD. Two hundred patients were assigned to either a PTSD group (n = 100) or to a non-PTSD control group (n = 100). Standard clinical profiles demonstrated that the PTSD group had overall higher mean elevations and an 8-2 configuration. A discriminant function analysis based on an empirically derived decision rule correctly classified 74% of the patients in each group. A special PTSD subscale was developed and cross-validated that improved diagnostic hit rates to 82% of the patients. The discriminant validity of the diagnosis of PTSD and the use of psychological tests in the assessment of Vietnam combat veterans are discussed. In the only major epidemiological study of the psychological and social condition of Vietnam veterans, the Center for Policy Research (Egendorf, Kadushin, Laufer, Rothbart, & Sloan, 1981) found high rates of maladjustment among combatants of the Vietnam war. In recent years, these combat veterans have been seeking treatment for their psychological problems in unprecedented numbers (cf. Fairbank & Keane, 1982; Keane & Kaloupek, 1982). Unfortunately, little research exists to guide the clinician in conducting an assessment for combat-related disorders. The purpose of the present study was to examine the usefulness of the Minnesota Multiphasic Personality Inventory (MMPI) in detecting the symptoms of combat-relate d posttraumatic stress disorder (PTSD). In a previous study from our laboratory, Fairbank, Keane, and Malloy (1983) compared the responses of three different groups of Vietnam-era veterans on the MMPI: (a) Vietnam combat veterans with a reliable diagnosis of PTSD, (b) well-adjusted Vietnam