Important differences in clinical practice exist between psychiatrists and psychologists. However, there is scarce information on the characteristics of patients receiving treatment from these two groups of professionals. We examined the diagnoses assigned to the patients who received treatment from psychiatrists and psychologists in outpatient settings of Madrid, Spain, from 1980 to 2008. The psychologists were more likely to see anxiety-related disorders, whereas the psychiatrists tended to see disorders with a more prominent biological underpinning, such as schizophrenia or bipolar disorder. The profile of the patients seen by the psychologists is different from that of the psychiatrists. Disorders whose development is more related to distress were usually treated by the psychologists, whereas disorders with a more prominent biological underpinning were usually treated by the psychiatrists. In addition, the dramatic increase in the diagnosis of adjustment disorder might be related to the increasing "psychologization" and "medicalization" of the difficulties of everyday life.