Patients with a psychiatric disorder are known to make greater use of medical resources than patients without a psychiatric condition, but the impact of highly prevalent psychiatric illnesses, such as depression, on use of medical resources has not been fully explored. This study assessed the lengths of stay of 92 medical and surgical patients who met DSM-III criteria for depression and the relationship of their length of stay to the timing of psychiatric consultations. The 92 patients were hospitalized significantly longer (a mean of 2.52 days more) than they would have been had their length of stay been determined by their medical diagnosis-related group (DRG). A subgroup of 38 Medicare patients were hospitalized a mean of 5.22 days more than the mean stay allowed by their DRG. Consultations occurring earlier in the hospitalizations were linked to shorter stays.