Who is identified when screening for depression is undertaken in general practice? Baseline findings from the Diagnosis, Management and Outcomes of Depression in Primary Care (diamond) longitudinal study.

Objectives: To report the baseline characteristics of the Diagnosis, Management and Outcomes of Depression in Primary Care (diamond) study cohort and discuss the implications for depression care in general practice. Design: A prospective longitudinal study beginning in January 2005. Participants and setting: Adult patients with depressive symptoms identified via screening with the Center for Epidemiologic Studies Depression Scale (CES-D >= 16) in 30 randomly selected Victorian general practices. Main outcome measure: Depression status on the Patient Health Questionnaire (PHQ). Results: 789 patients form the cohort (71 % women). At baseline, 47% were married, 21 % lived alone, 36% received a pension or benefit, 15% were unable to work, 23% reported hazardous drinking, 32% were smokers, 39% used antidepressants and 19% used sedatives. 27% satisfied criteria for current major depressive syndrome (MDS) on the PHQ, while 52% had 'persistent' depressive symptoms, and 22% had 'transient' depressive symptoms, lasting at most a few weeks. Of those satisfying criteria for MDS, 49% were also classified with an anxiety syndrome, 40% reported childhood sexual abuse, 57% reported childhood physical abuse, 42% had at some time been afraid of their partner, and 72% reported a chronic physical condition; 84% were receiving mental health care (either taking antidepressants or seeing a health practitioner specifically for mental health care) compared with 66% of those with persistent depressive symptoms and 57% with transient depressive symptoms. Conclusion: This method of screening for depressive symptoms in general practice identifies a group of patients with substantial multiple comorbidities - psychiatric, physical and social problems coexist with depressive symptoms, raising challenges for the management of depression in general practice.