Physicians' attitudes, diagnostic process and barriers regarding depression diagnosis in primary care: a systematic review of qualitative studies

Findings of diagnostic studies using standardized psychiatric interviews as a gold standard suggest that family physicians (FPs) both under- and over-diagnose depression. We systematically reviewed qualitative studies investigating how FPs diagnose depression and what their concepts of depression and the perceived barriers are when diagnosing depression. We searched Medline, Embase, PsychInfo, reference lists and family practice journals to identify qualitative studies on primary care providers addressing at least one of the following issues: concepts, process and barriers relevant to diagnosing depression. Thematic synthesis was used for collecting data by line-by-line coding of the findings of the primary studies and for the development of descriptive and analytical themes. Thirteen qualitative studies interviewing a total of 239 primary care providers met the inclusion criteria. Three distinct themes with nine subthemes that specify attitudes, diagnostic process and barriers while diagnosing depression were identified. The synthesis revealed that FPs use approaches to diagnose depression that are usually based on their knowledge of the patient's long-term history, an established patient-doctor relationship and a rule-out algorithm of other diagnoses. As such, these strategies markedly differ from the diagnostic criteria for depressive disorders that are used in psychiatrically oriented classification systems. FPs believe to have sensible strategies for diagnosing depression that are different from the concepts operationalized in psychiatrically oriented classifications. In diagnostic studies, considering standardized psychiatric interviews uncritically as a gold standard for diagnosis of depression in primary care might be misleading.