A review of empiric studies of the stresses of residency training and descriptions of intervention programs and mental health resource surveys published since 1980 indicated that inadequate sleep and fatigue are major stressors for residents, but they are only part of a more complex situation influenced by time demands, social support, and maturational factors. Other important stressful aspects of training appear to be those that interfere with social support. Increased anger, not depression, is emerging as the predominant mood change during residency, but the effects of any mood change on patient care have not been studied. Despite growing evidence of the need for change in training programs, especially attention to the affiliative needs of residents, few intervention programs have been reported.