The advent of clinical practice guidelines for depression in primary care and psychiatry increases the importance of understanding variation across clinician specialty groups in treatment style for depression and for different types of depressed patients. Using data from the Medical Outcomes Study, the authors examined clinician proclivities (e.g., attitudes) and actual practice patterns for prescribing antidepressant medications and counseling their depressed outpatients with and without medical comorbidities (recent myocardial infarction, hypertension, or diabetes). Data are from clinician self-report (N=470), encounter forms completed by clinicians after patient visits (N=4,813) and patient self-report (N=2,201). The authors used multiple regression to compare treatment style for psychiatrists, medical subspecialists, family practitioners, general internists, psychologists, and non-medical therapists. Family practitioners reported proclivities to medicate that were similar to psychiatrists but in actual practice, the medication rate was higher for psychiatrists. Mental health specialists reported the highest proclivity to counsel and provided the most counseling in actual practice. Relative to other primary care specialties, family practitioners had the highest proclivity to counsel and to medicate; internists and subspecialists had similar proclivities to medicate but compared to internists, subspecialists had a lower proclivity to counsel. Patterns of specialty differences in proclivities held for patients with or without medical comorbidity, but across specialties, clinician proclivity to medicate was lowest for patients with depression plus myocardial infarction, compared to depressed patients with no medical comorbidity or other types of medical comorbidity. Results emphasize the importance to clinician and patient education interventions for improving the treatment of depression.