A systematic review of the impact of flooding on mental health outcomes among diverse populations in Nigeria

Abstract

Flooding represents the most recurrent and devastating natural hazard in Nigeria, affecting millions of individuals annually with consequences that extend beyond physical destruction to profound psychological impairment. Despite the escalating frequency and severity of flood events, the mental health dimensions of flooding remain systematically under-researched and under-prioritized within Nigerian disaster response frameworks. This systematic review aimed to synthesise existing evidence on the mental health outcomes associated with flooding among diverse populations in Nigeria. A comprehensive search of Scopus, PubMed, ScienceDirect, Springer, AJOL, and BMC databases was conducted for peer-reviewed studies published between 2015 and 2026. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Data were synthesised using thematic analysis. Twelve studies met the inclusion criteria, spanning populations including internally displaced persons, children, farmers, elderly individuals, and community residents across multiple Nigerian states. The evidence consistently demonstrated elevated prevalence of post-traumatic stress disorder, depression, anxiety, and general psychological distress among flood-affected populations. Key determinants included displacement status, property loss, gender, age, educational attainment, and social support availability. Flooding in Nigeria is associated with a significant and multifaceted mental health burden across diverse population subgroups. The evidence underscores the urgent necessity for integrating mental health and psychosocial support into national disaster preparedness and response frameworks. Targeted interventions for vulnerable groups, including children, women, and the elderly, are essential components of comprehensive flood response strategies.