Background. Despite the need for rational allocation of resources and cooperation between different treatment settings, clinical differences in patients with major depressive disorder (MDD) between primary and psychiatric care remain obscure. We investigated these differences in representative patient populations from primary care versus secondary level psychiatric care in the city of Vantaa, Finland.

Method. We compared MDD patients from primary care in the Vantaa Primary Care Depression Study (PC-VDS) (n=79) with psychiatric out-patients (n=223) and in-patients (n=46) in the Vantaa Depression Study (VDS). DSM-IV diagnoses were assigned by the Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I in PC-VDS) or Schedules for Clinical Assessment in Neuropsychiatry (SCAN in VDS), and SCID-II interviews. Comparable information was collected on depression severity, Axis I and II co-morbidity, suicidal behaviour, preceding clinical course, and attitudes towards and pathways to treatment.

Results. Prevalence of psychotic subtype and severity of depression were highest among in-patients, but otherwise few clinical differences between psychiatric and primary care patients were detected. Suicide attempts, alcohol dependence, and cluster A personality disorder were associated with treatment in psychiatric care, whereas cluster B personality disorder was associated with primary care treatment. Patients' choice of the initial point of contact for current depressive symptoms seemed to be independent of prior clinical history or attitude towards treatment.

Conclusions. Severe, suicidal and psychotic depression cluster in psychiatric in-patient settings, as expected. However, MDD patients in primary care or psychiatric out-patient settings may not differ markedly in their clinical characteristics. This apparent blurring of boundaries between treatment settings calls for enhanced cooperation between settings, and clearer and more structured division of labour.