Childhood adversities, negative life events and outcomes of non-pharmacological treatments for depression in primary care: A secondary analysis of a randomized controlled trial

Abstract

Non-pharmacological treatments for depression are effective and available in primary care, but useful prognostic factors are lacking. Childhood adversities (CA) and negative recent life events (RLE) increase the risk and severity of depression, though their effect on treatment outcomes remains understudied. Using a sample of 737 adult participants of a multicenter randomized controlled trial receiving physical exercise, internet based cognitive-behavioral therapy or treatment as usual, alone or in combination with antidepressants, this prospective study aimed to determine the impact of CA, RLE and their interaction as predictors of outcomes of non-pharmacological treatments for mild-moderate depression in primary care. Outcomes were depression severity (MADRS score) and response to treatment (≥50% reduction in MADRS score) after three months. Linear regression and modified Poisson regression were used, interaction was assessed with a product term (CA*RLE) and epidemiological measures of interaction. The number of CA and RLE were associated with higher depression severity at follow-up (CA: β = 0.79, 95% CI: 0.14 to 1.44 and RLE: β = 0.52, 95% CI: 0.14 to 0.72) and showed a trend towards lower rates of response to treatment (RR = 0.94, 95% CI: 0.86 to 1.03; and RLE: RR = 0.95, 95% CI: 0.90 to 0.99). Interaction between CA and RLE was not significant for depression severity (β = 0.10, 95% CI: −2.12 to 0.41) nor for response to treatment (RERI = −0.05, 95% CI = −0.33 to 0.24). CA and RLE are associated with worse outcomes of non-pharmacological treatments in primary care. Further studies to identify predictors of outcomes of non-pharmaological treatments for depression are needed.