Incidence of Major Depressive Disorder Relapse and Effectiveness of Pharmacologic and Psychological Interventions in Primary Care: A Systematic Review and Meta-Analysis: Incidence de la rechute du trouble dépressif majeur et efficacité des interventions pharmacologiques et psychologiques en soins primaires : revue systématique et méta-analyse

Objective This research aims to investigate the relapse rates of major depressive disorder (MDD) within primary care and evaluate the efficacy of relapse prevention therapies. Despite primary care being the common point of contact for MDD patients, there are limited studies around this.Methods We included randomized controlled trials and observational studies examining MDD relapse incidence and the effect of pharmacological and non-pharmacological interventions in preventing relapse in primary care. Databases; Medline via Ovid, EMBASE, The Cochrane Library, PsycInfo (ebsco), and Clinical Trials.gov were searched from their inception until September 7, 2022. Joanna Briggs Institute (JBI) appraisal instrument for methodological quality assessment was used. A proportional data analysis estimated the MDD relapse incidence. Therapy effectiveness results were shown as odds ratios with 95% confidence intervals, with heterogeneity explored via subgroup analysis.Results Out of the reviewed studies, 35 met the eligibility criteria. Quality appraisal scores varied between 73% and 96%. MDD relapse incidence was divided into subgroups, revealing that both pharmacotherapy and non-pharmacotherapy led to a similar decrease in relapse rates with combination therapies showing further reduction in relapse. Subgroup analyses by study design, follow-up length, date of study and quality of study also yielded noteworthy findings.Conclusion Our findings showed that MDD relapse rates in primary care settings can be effectively reduced by pharmacotherapy, non-pharmacotherapy, or combination therapy. Some psychological interventions might also reduce relapse likelihood. More studies are needed on individual and combined treatments over longer periods to understand their long-term impacts on MDD relapse in primary care.