The ten-year course of depression in primary care and long-term effects of psychoeducation, psychiatric consultation and cognitive behavioral therapy

Background While the majority of depressed patients are treated in primary care, long-term follow-up data on the naturalistic course of depression and treatment effectiveness in this setting are scarce. This study examined the ten-year course of depression in primary care patients who had participated in a randomized clinical trial aiming at enhancement of depression outcomes.

Methods Of the original sample (n=267), 166 patients participated in the ten-year follow-up; missingness was random. Four treatments were compared: (1) Care As Usual (CAU; n=51); (2) a Psychoeducational Prevention program (PEP; n=68); (3) Psychiatric Consultation followed by PEP (PC+PEP; n=21); and (4) brief Cognitive Behavioral Therapy followed by PEP (CBT+PEP; n=26). During the first three years interviews based on the Composite International Diagnostic Interview (CIDI) were three-monthly applied, the seven years thereafter were assessed with a once applied CIDI and a face-to-face life chart-based interview.

Results During the ten-year follow-up 76.5% of the patients developed a new depressive episode, 83.4% used antidepressants (median usage 3.1 years), median depression diagnosis-free time was 9.0 years, and median residual symptom-free time 3.8 years. Treatments did not significantly differ on these outcomes, only trends appeared for lower depression severity for CBT+PEP, and, along with PEP, a higher proportion of symptom-free time.

Limitations Assessment with the once applied life chart interview (a valid and reliable instrument) is less precise than the three-monthly assessments during the first three years.

Conclusions The long-term course of depression in primary care is unfavorable, whereas treatment effects over time seem absent or small.