Background. The long-term outcome of major depression is often unfavorable, and because most cases of depression are managed by general practitioners (GPs), this places stress on the need to improve treatment in primary care. This study evaluated the long-term effects of enhancing the GP's usual care (UC) with three experimental interventions.

Method. A randomized controlled trial was conducted from 1998 to 2003. The main inclusion criterion was receiving GP treatment for a depressive episode. We compared: (1) UC (n=72) with UC enhanced with: (2) a psycho-educational prevention (PEP) program (n=112); (3) psychiatrist-enhanced PEP (n=37); and (4) brief cognitive behavioral therapy followed by PEP (CBT-enhanced PEP) (n=44). We assessed depression status quarterly during a 3-year follow-up.

Results. Pooled across groups, depressive disorder-free and symptom-free times during follow-up were 83% and 17% respectively. Almost 64% of the patients had a relapse or recurrence, the median time to recurrence was 96 weeks, and the mean Beck Depression Inventory (BDI) score over 12 follow-up assessments was 9·6. Unexpectedly, PEP patients had no better outcomes than UC patients. However, psychiatrist-enhanced PEP and CBT-enhanced PEP patients reported lower BDI severity during follow-up than UC patients [mean difference 2·07 (95% confidence interval (CI) 1·13–3·00) and 1·62 (95% CI 0·70–2·55) respectively] and PEP patients [2·37 (95% CI 1·35–3·39) and 1·93 (95% CI 0·92–2·94) respectively].

Conclusions. The PEP program had no extra benefit compared to UC and may even worsen outcome in severely depressed patients. Enhancing treatment of depression in primary care with psychiatric consultation or brief CBT seems to improve the long-term outcome, but findings need replication as the interventions were combined with the ineffective PEP program.