Post-traumatic stress disorder (PTSD) is a serious, complex anxiety disorder that may result from exposure to significant natural and social trauma, including war. Approximately 500,000 (15%) or more of Vietnam veterans in the United States are afflicted with this disorder presenting an immediate and long term health problem of major proportions that impacts on nurses, psychologists, and other health professionals. The long-term objectives of this proposal are: a) to provide the most effective forms of a care and diagnosis for combat-related PTSD in the multi-ethnic population of Vietnam veterans utilizing the Veterans Administration (VA) Medical Center in Hawaii; b) to promote research on treatment and assessment alternatives for stress-related disorders, especially emphasizing "multi-modal" approaches, and c) to enhance research and training opportunities and resources for students and faculty in the School of Nursing and Health Psychology programs at the University of Hawaii. These objectives will be addressed through collaborative research between the School of Nursing, Department of Psychology, and VA Medical Center that aims specifically to: 1) assess PTSD in a population of Vietnam veterans representing Pacific Islanders, Asian-Americans, and Caucasians; b) employ diagnostic instruments that target physiological, behavioral, and cognitive modes of PTSD; and c) perform controlled clinical research that compares biofeedback-assisted relaxation training and 'imaginal flooding' methods with treatments that emphasize routine clinical care and control for attentional effects. In each experiment, male Vietnam veterans with a diagnosis of PTSD will be assigned to treatment and control conditions in equal numbers to cells representing the three ethnic subgroups. Following preliminary and baseline assessment, in the first experiment, a general relaxation intervention including multi-muscle biofeedback training will be applied. In a second experiment, an imaginal-flooding intervention will be applied that emphasizes the repeated rehearsal of trauma-laden memories and attendant emotional arousal. In both studies, the treatment effects will be assessed using physiological and questionnaire-interview instruments. In addition, the experimental design allows for treatment to be provided for the control subjects, ensuring equitable treatment for all subjects and optimum utilization of the subject population for treatment and multi- ethnic comparisons. The results of this research will have implications for behavioral (associative learning) and psychophysiological theories of stress-related disorders, and will foster the development of future treatment and assessment strategies for this serious disorder.