Psychological Treatments for Persistent Depression: A Systematic Review and Meta-Analysis of Quality of Life and Functioning Outcomes

To date it is unclear whether psychological therapies have potential to improve quality of life and functioning in patients with persistent depression. This meta-analysis examines the effect of psychological therapies for improving quality of life and functioning in patients with persistent forms of depression. Data sources include Medline and Meta-Analytic Psychotherapy Database (METAPSY), searched 07/2021. Eligible studies were randomized controlled trials where participants had major depressive disorder on entry and met criteria for a persistent form of depression, for example, chronic, treatment resistant or recurrent depression. Standardized mean differences (Hedge's g) were calculated in random-effects meta-analyses. Fourteen studies met inclusion criteria (N = 1898). Psychological interventions were associated with improvements in patients' quality of life at the end of treatment: pooled g = 0.24 (95% confidence intervals [CIs] 0.13-0.34); low to moderate levels of heterogeneity (I2 = 0% [95% CI 0%-41.2%]). Quality of life at follow-up: pooled g = 0.21 (95% CI 0.10-0.32); low to high levels of heterogeneity considering the wide CI for I2 (I2 = 10.36% [95% CI 0%-77.5%]). The psychological interventions were associated with improvements in patients' functioning at end of treatment: pooled g = 0.35 (95% CI 0.21-0.48); low to high levels of heterogeneity considering the wide CI for I2 (I2 = 0% [95% CI 0%-81.7%]). Functioning at follow-up resulted in: pooled g = 0.33 (95% CI 0.15-0.51); low to high levels of heterogeneity considering the wide CI for I2 (I2 = 0% [95% CI 0%-86.2%]). This meta-analysis highlights the potential benefits of psychological therapies for improving quality of life and functioning in patients with persistent depression, with strongest long-term effects for mindfulness-based cognitive therapy, interpersonal therapy in combination with antidepression medication, and long-term psychoanalytic psychotherapy. Clinical Impact Statement Question: Are psychological therapies associated with improvements in quality of life and functioning in patients with persistent forms of depression? Findings: Our meta-analyses suggest that some psychological therapies (e.g., MBCT, LTPP, and IPT in combination with medication) have a moderate positive effect on patients' quality of life and functioning, both at the end of treatment and at follow-up. Meaning: Psychological treatments do not always demonstrate the same degree of impact on patients' quality