Mental Health and Psychosocial Support in Public Health Emergencies: A Critical Narrative Review of Effectiveness and Service Delivery Innovation

Public health emergencies generate diverse mental health and psychosocial needs while disrupting the services required to address them. This critical narrative review examines intervention effectiveness and the conditions needed to translate evidence into sustainable service delivery. Targeted PubMed searches conducted on 24 October 2026 supplemented an existing bibliography, with purposive selection of relevant systematic reviews, meta-analyses and authoritative guidance. Evidence was interpreted by population, comparator, outcome and implementation context; no new meta-analysis or formal certainty assessment was undertaken. Selected psychological interventions reduced post-traumatic stress symptoms in displaced and disaster-affected populations, but heterogeneity and variable controls limit comparisons between approaches. Evidence for low-intensity transdiagnostic programmes differed across populations, and reported benefits frequently rested on very-low-certainty evidence. Digital interventions improved some symptom outcomes during COVID-19, without establishing equitable access or durable system-wide effectiveness. Recent implementation evidence supports the acceptability and feasibility of Problem Management Plus, while highlighting gaps in cost, adoption and sustainability. The review proposes an unvalidated service development framework linking clinical matching, supervised task sharing, accessible delivery, referral continuity and outcome monitoring. Its application to Saudi Arabia requires local adaptation and evaluation rather than direct transfer of effect estimates. Innovation should be judged by sustained clinical and functional benefit, equitable reach and operational viability, rather than programme uptake alone.