Effectiveness of grief interventions in underrepresented regions: a systematic review and exploratory meta-analysis

Background: Most evidence on grief and bereavement interventions originates from Western, Educated, Industrialized, Rich, and Democratic (WEIRD) populations, raising concerns about the generalizability and cultural relevance of existing findings in diverse global contexts. Individuals confronted with the death of a close person, particularly in cases of sudden or potentially traumatic loss, may be at increased risk of adverse psychological and physical health outcomes, highlighting the importance of effective interventions. This study aimed to synthesize evidence on the effectiveness of grief interventions in underrepresented regions.Method: A systematic search of Web of Science, APA PsycInfo, and Scopus, supplemented by manual reference checks, identified randomized controlled trials (RCTs) targeting bereaved individuals in underrepresented regions. Meta-analyses were conducted to estimate overall and subgroup effects based on control type, loss type, and intervention characteristics.Results: Fourteen RCTs comprising 1122 participants were included. Grief interventions demonstrated a significant moderate-to-large effect compared to control conditions (SMD = -0.74, 95% CI [-1.01, -0.47]). Substantial heterogeneity was observed (I² = 77%). No significant subgroup differences were identified.Conclusion: Grief interventions show promising effectiveness across diverse cultural and geographical contexts. However, the limited and heterogeneous evidence base highlights the need for more high-quality RCTs and for the development of culturally sensitive and contextually grounded approaches to mental health care in underrepresented regions.