To examine the need for preventive and treatment interventions, a prevalence study was conducted to ascertain the rate of depressive symptomatology and other negative mood states among 112 first-year residents. The participation rate was 54%. Subjects (N = 61) were administered the Beck Depression Inventory and Profile of Mood States in personal interview sessions. The Profile measures five negative mood states, namely, "tension-anxiety," "depression-dejection," "anger-hostility," "fatigue-inertia," "confusion-bewilderment," and one positive state, "vigor-activity." A 15.5% rate of depression was found, which is lower than a rate of 23.5%, also measured by Beck's inventory, among a sample of university undergraduates and 19.9% among an adult sample from the general population. No differences were observed among residency programs or sex on Beck's scale; however, significantly higher scores were found for women on the "depression-dejection" dimension of the Profile. The mean scores on all negative mood dimensions of the Profile were below the mean for university undergraduate norms. Neither sleep nor hours worked over the past week were associated with increased Beck scores. These results indicate that sleep deprivation and long work hours did not contribute to depression among the subjects who participated in the study. Female interns, however, appear to be at increased risk of depression, and adequate support systems need to be provided.