What is depression? Psychiatrists' and GPs' experiences of diagnosis and the diagnostic process.

The diagnosis of depression is defined by psychiatrists, and guidelines for treatment of patients with depression are created in psychiatry. However, most patients with depression are treated exclusively in general practice. Psychiatrists point out that general practitioners' (GPs') treatment of depression is insufficient and a collaborative care (CC) model between general practice and psychiatry has been proposed to overcome this. However, for successful implementation, a CC model demands shared agreement about the concept of depression and the diagnostic process in the two sectors. We aimed to explore how depression is understood by GPs and clinical psychiatrists. We carried out qualitative in-depth interviews with 11 psychiatrists and 12 GPs. Analysis was made by Interpretative Phenomenological Analysis. We found that the two groups of physicians differed considerably in their views on the usefulness of the concept of depression and in their language and narrative styles when telling stories about depressed patients. The differences were captured in three polarities which expressed the range of experiences in the two groups. Psychiatrists considered the diagnosis of depression as a pragmatic and agreed construct and they did not question its validity. GPs thought depression was a "gray area" and questioned the clinical utility in general practice. Nevertheless, GPs felt a demand from psychiatry to make their diagnosis based on instruments created in psychiatry, whereas psychiatrists based their diagnosis on clinical impression but used instruments to assess severity. GPs were wholly skeptical about instruments which they felt could be misleading. The different understandings could possibly lead to a clash of interests in any proposed CC model. The findings provide fertile ground for organizational research into the actual implementation of cooperation between sectors to explore how differences are dealt with.