Among a sample of 767 high utilizers of health care, 51% were identified as distressed by an elevated score on the SCL anxiety and depression scales, the SCL somatization scale, or by their primary-care physician. These distressed high utilizers were found to have a high prevalence of chronic medical problems and significant limitation of activities caused by illness. In the prior year, they made an average of 15 medical visits and 15 telephone calls to the clinic. The Diagnostic Interview Schedule was completed on 119 distressed high utilizers randomly assigned to an intervention group in a controlled trial of psychiatric consultation. The following DSM-III-R disorders were most common: major depression 23.5%, dysthymic disorder 16.8%, generalized anxiety disorder 21.8%, and somatization disorder 20.2%. Two thirds had a lifetime history of major depression. The examination resulted in an improved diagnostic assessment for 40% of intervention patients and a revised treatment plan for 67%.