Background: Psychoeducational interventions are increasingly implemented to promote psychological and physical health, yet evidence guiding personalized intervention selection remains limited. This systematic review and meta-analysis quantifies the effectiveness of psychoeducational interventions across five settings and identifies empirically derived moderator patterns to inform the selection of tailored interventions. Methods: Systematic searches of PubMed/MEDLINE, PsycINFO, Scopus, Web of Science, ERIC, the Cochrane Library, and Google Scholar were conducted to identify eligible studies published between January 2015 and December 2024. A two-tier analytical approach was employed: a random-effects meta-analysis of k = 53 studies reporting extractable effect-size data, and a direction-of-effect narrative synthesis of all 186 included studies (N = 50,328 verified from 124 studies reporting sample sizes), following SWiM guidelines. Results: The quantitative meta-analysis yielded a significant medium-to-large pooled effect (g = 0.66, 95% CI 0.50, 0.82, p < 0.001) with substantial heterogeneity (I2 = 96.1%). Effects varied across settings: clinical/vulnerable populations showed the largest effect (g = 0.91), followed by university programs (g = 0.62), school-based (g = 0.60), mindfulness/positive psychology (g = 0.55), and community-based (g = 0.49). The broader narrative synthesis confirmed near-universal effectiveness: 131 studies (70.4%) reported significant positive effects, 51 (27.4%) reported mixed results, and none reported null effects—yielding 97.8% favorable outcomes across the full evidence base. Direction-of-effect moderator patterns indicated a stepped severity gradient (indicated 100% favorable, selective 98.6%, universal 95.6%), and that programs exceeding 8 weeks (99.0% vs. 96.6%), theory-based interventions (98.2% vs. 95.2%), and guided digital delivery were consistently associated with the most favorable outcomes. Publication bias assessment confirmed robustness (fail-safe N = 22,942; leave-one-out range: 0.61–0.67). GRADE evidence quality was rated Moderate for four of five research questions. Conclusions: This systematic review and meta-analysis provide converging quantitative and direction-of-effect evidence supporting the effectiveness of psychoeducational interventions. The near-universal favorable direction across 186 studies, combined with a medium-to-large pooled effect in the quantitative subset, provides a preliminary empirical foundation for personalized intervention matching. A preliminary four-phase implementation framework is proposed as a hypothesis-generating heuristic; prospective validation through a meta-analysis of individual participant data is needed before prescriptive application.
Gkintoni et al. (Tue,) studied this question.