Psychological Interventions for the Prevention of Major Depression: An Individual Participant Data Meta-Analysis

The project investigates the effectiveness of psychological interventions for preventing major depressive disorder in adults who already experience clinically relevant subthreshold depressive symptoms but do not meet criteria for major depressive disorder at baseline. To this end, individual participant data from randomized controlled trials conducted internationally are systematically identified, pooled, and harmonized.
Using an individual participant data meta-analysis, the project examines short- and longer-term intervention effects on the first or recurrent onset of major depressive disorder, depressive symptom severity, and clinically meaningful symptom change. A further focus is the analysis of potential effect modifiers at the participant and study levels, including sociodemographic and clinical characteristics, previous experience with psychotherapy, and characteristics of the interventions and their delivery. We will also examine, as a foundation for potential future precision mental health, machine-learning based prediction models, to predict intervention success on an individual level.
The statistical analyses account for the hierarchical structure of the data, between-study differences, and missing data, and are complemented by sensitivity analyses. The overarching aim is to strengthen the evidence base for indicated prevention of depressive disorders and to identify approaches for targeted, personalized, and routinely implementable prevention services.