The primary purpose of this study was to assess the prevalence of major psychiatric disorders in human immunodeficiency virus-positive (HIV+) men with acquired immune deficiency syndrome (AIDS)-defining conditions. Secondary goals were to identify correlates of distress and psychopathology, and to determine whether there is a gradient of distress associated with progressive HIV illness. One hundred twelve men with AIDS-defining conditions, 61 HIV+ men without AIDS, and 84 HIV-seronegative gay men were assessed. Measures included the Structured Clinical Interview for DSM-IV (SCID), Hamilton Rating Scale for Depression (HAM-D), and other dimensional measures of distress and outlook, as well as laboratory markers of HIV stage, including HIV RNA viral load assays. Rates of major depression, consistent with other findings, were in the 5% to 10% range. Mean scores on dimensional measures of distress and outlook were within the "not depressed" range and did not increase despite increasing HIV illness severity. However, rates of dysthymia were elevated among men with CD4 cell counts less than 500, and the cumulative rates of any current axis I depressive disorder for three of the four study groups were in the range of 15% to 20%. The strongest correlates of dimensional measures of distress were current HIV symptoms and social support, and to a lesser extent, a lifetime history of major depression and current use of antidepressants and/or anxiolytics. Overall, most men displayed effective adaptation to illness, but a significant minority experienced moderate psychological distress, which warrants consideration by health providers who serve this population.