BACKGROUNDTo the authors' knowledge, there have been few studies of the psychologic distress after disclosure of genetic test results for hereditary nonpolyposis colorectal carcinoma (HNPCC). The objectives of this study were to identify the prevalence rates and predictors of psychologic distress and to evaluate the feelings of guilt after disclosure of the test results in Japanese probands and unaffected relatives.METHODSProbands and unaffected relatives were interviewed immediately after the first genetic counseling session for HNPCC and again 1 month after disclosure of the genetic test results. The prevalence of major and minor depression, acute stress disorder (ASD), posttraumatic stress disorder (PTSD), and posttraumatic stress symptoms (PTSS) were assessed using the Structured Clinical Interview based on the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition revised (DSM‐III‐R) or the DSM‐IV; feelings of guilt were investigated using a numeric scale and a semistructured interview.RESULTSAmong 47 participants who completed the baseline interview, 42 participants (89%) completed the 1‐month follow‐up interview. Although none of the participants met the criteria for major depression, ASD, or PTSD at the follow‐up interview, 3 of 42 participants (7%) met the criteria for minor depression and 2 participants (5%) had PTSS. The only predictor of psychologic distress found was the presence of a history of major or minor depression (odds ratio, 19.41; 95% confidence interval, 1.42–264.95; P < 0.05). Five of 42 participants (12%) had feelings of guilt.CONCLUSIONSDisclosure of genetic test results for HNPCC may not cause significant psychologic distress in Japanese probands or relatives. However, healthcare providers should not neglect to assess these individuals for psychologic responses, such as minor depression and PTSS. Cancer 2004. © 2004 American Cancer Society.