Underrecognition of mental disorders by primary care physicians is well-documented to be in the range of 50-80%. The aim of this study is to clarify the reasons for the underrecognition of depression, the most prevalent and the most often overlooked of the ental disorders. Non-recognition represents significant extended pain and morbidity and a substantial financial burden on the health care industry. It is incumbant on the health profession to identify the factors which explain this phenomenon in order to correct it at its source. Poor clinical practice undoubtedly accounts for most underrecognition and misdiagnosis. Yet, there is a lack of well designed studies which have explored how the accuracy of physicians' diagnoses is related to their knowledge base, interviewing skills and behavior, or attitudes toward depression as a disorder, all of which are the focus of this proposal. Major strengths of our research design are the use of standardized" patients, thus controlling for undesirable patient variability, and community-based, rather than resident or academic, physicians. Fifty physicians will each interview six "patients," whose scripts will include presentations which are typical in primary care; four "patients" will be depressed, two will have medical diagnoses without depression. The 300 encounters will be videotaped; the behavioral aspects of the interview will be obtained through the Interaction System for Interview evaluation (ISIE) and the content will be obtained through a patient post-encounter checklist. Accuracy of diagnosis will be obtained on a standardized physician debriefing form at the close of each patient encounter. Measures of the physician characteristics will be obtained at the conclusion of each set of six patient encounters. The specific aims for the preliminary and exploratory studies are as follows: AIM 1: To develop an inventory to measure past psychiatric/behavioral science training during residency; AIM 2: To develop convincing scripts for standardized primary care patients; AIM 3: To establish training procedures for the standardized patients; AIM 4: From the standardized scripts, to develop patient checklists to measure the content of he medical interview; AIM 5: To pilot the procedures for the doctor/patient encounters nd the administration of the data collection instruments; AIM 6: To recruit a sample of 50 physicians for the exploratory study; AIM 7: To explore the preliminary research hypotheses on a sample of 50 community-based primary care physicians.