Psychological treatment of adult depression in primary care compared with outpatient mental health care: A meta-analysis

Background: It is not yet known whether psychological treatments of depression in primary care have comparable effects to treatments in specialized mental health care. We conducted a meta-analysis comparing randomized controlled trials in primary and specialized care. Methods: We selected studies from an existing database of randomized trials of psychological treatments of depression in adults, which was built through searches in PubMed, PsychINFO, Embase and the Cochrane Library. Random effects meta-analyses were conducted to examine the effects of therapies and mixed effects subgroup analyses were used to compare the effects in primary and specialized care. Results: We included 52 trials (7984 patients) in primary care and compared them with 50 trials (3685 patients) in specialized care. The main effect of therapies in primary care was g = 0.43 (95 % CI: 0.32; 0.53; PI: −0.18; 1.03). The overall effects were significantly smaller than those in specialized care (p = 0.006), but this was no longer significant after adjustment for differences between the two settings. The proportion of patients responding to treatment was comparable in primary (0.38; 95 % CI: 0.33; 0.43) and specialized care (0.34; 95 % CI: 0.28; 0.41; p = 0.41), but higher in control conditions in primary care (0.25; 95 % CI: 0.22; 0.28) compared to specialized care (0.16; 95 % CI: 0.12; 0.20; p < 0.001). Discussion: Psychological treatments are effective in primary care, but somewhat less than in specialized care. Response rates in control conditions in primary care are higher than in specialized care, which may point at a transient nature of depression in primary care.