Diagnosing depression: there is no blood test.

Objective: To explore and describe primary care physicians' experiences in providing care to depressed patients and to increase understanding of the possibilities and constraints around diagnosing and treating depression in primary care.

Design: Qualitative study using personal interviews.

Setting: A hospital region in eastern Canada.

Participants: A purposely diverse sample of 20 physicians chosen from among all 100 practising family physicians in the region.

Method: Invitations were mailed to all physicians practising in the region. Twenty physicians were chosen from among the 39 physicians responding positively to the invitation. Location of practice, sex, and year of graduation from medical school were used as sampling criteria. The 20 physicians were then interviewed, and the interviews were audiotaped and transcribed verbatim. Data were analyzed using a constant comparative approach involving handwritten notes on transcripts and themes created using qualitative data analysis software.

Main Findings: Three themes related to diagnosis emerged. The first concerns use of checklists. Physicians said they needed an efficient but effective means of diagnosing depression and often used diagnostic aids, such as checklists. Some physicians, however, were reluctant to use such aids. The second theme, interpersonal processes, involved the investment of time needed for diagnosing depression and the importance of establishing rapport. The final theme, intuition, revealed how some physicians relied on "gut sense" and years of experience to make a diagnosis.

Conclusion: Diagnosis of depression by primary care physicians involves a series of often complicated negotiations with patients. Such negotiations require expertise gained through experience, yet prior research has not recognized the intricacies of this diagnostic process. Our findings suggest that future research must recognize the complex and multidisciplinary nature of physicians' approaches to diagnosis of depression in order to better reflect how they practise.