Cognitive measures of Vietnam-era prisoners of war.

Approved for public release; distribution unlimited. To the Editor: Although some studies have found decreased cog-nitive performance in repatriated prisoners of vs^ar (POWS)/'^ other studies have not found such deficits.^-* Many of the studies that have found an intellectual decrement in POWs have meth-odological limitations, including failure to control for concurrent depression, posttraumatic stress disorder, or other mental illness; norurandom selection of participants who were umnoti-vated t9 malinger; lack of a controlgroup; and insufficient matching between POWs and controls.* In contrast, the largest investigation ,^ which smdied more than 2500 World War II and Korean War POWs, noted that evidence of organic brain syndrome was "conspicuously absent" from the diagnoses differentiating POWs from controls. More recendy, no cognitive differences were found on any cognitive test or on the computed axial tomography scans of POWs and controls.* We assessed the relative cognitive status of US Navy Vietnam-era POWs using data gathered by the Naval Operational Medicine Institute's ongoing POW research program. Methods. Case subjects were 138 naval aviator POWs who were repaoiated from North Vietnam in 1973. In 1976, the Navy invited 138 control subjects to participate in the aimual examination program. The controls were matched for age, year of commission, job code, education level, marital status, rank, number of flight hours, type of aircraft flown, and specific months flying combat missions. Informed consent was obtained prior to participation.^ During some years' aimual examinations , cognitive assessment was also included. Performance was compared between POWs and contirols on 3 cognitive batteries: the Halstead-Reitan Neuropsycho-logical Battery (HRNB), the Wechsler Adult Intelligence Scale (WAIS), and the CogScreen-Aeromedical Edition (AE). Although all POWs did not complete all 3 tests, each contirol was administered the same tests as his matched POW. The cases that had both matched-pair members with data on any of the 7 administrations of the 3 tests (117 matched pairs) were included in the study. Differences between groups and test sessions were assessed by multivariate analysis of variance. To assess whether POWs differed from controls on depression, the Minnesota Multiphasic Personality Inventory (MMPI) D score, which was obtained In the same testing session as the cognitive tests, was analyzed using an independent groups t test procedure. All analyses were, conducted using SPSS vlO.1.0 (SPSS Inc, Chicago; 111). Results. A comparison of the POWs and controls on 11 demographic variables revealed only 1 significant difference, with the control group having a mean of …