Evidence on the links between water insecurity, inadequate sanitation and mental health: A systematic review and meta-analysis

BACKGROUND: Water insecurity and inadequate sanitation have adverse impacts on the mental health of individuals. OBJECTIVE: To review and synthesize evidence on the relationship between water insecurity, inadequate sanitation, and mental health globally. DATA SOURCES: Relevant studies were identified by searching PubMed, PsycINFO, and EMBASE databases from inception up to March 2023. STUDY ELIGIBILITY CRITERIA: Only quantitative studies were included. The exposure was water insecurity and or inadequate sanitation. The outcome was common mental disorders (CMD: depression or anxiety), mental distress, mental health or well-being. There was no restriction on geographical location. PARTICIPANTS: General population or people attending health facilities or other services. EXPOSURE: Water insecurity and/ or inadequate sanitation. RISK OF BIAS: The effective Public Health Practice Project (EPHPP) assessment tool was used to assess quality of selected studies. SYNTHESIS OF RESULTS: A meta-analysis was conducted using a random effects statistical model. RESULTS: Twenty-five studies were included, with 23,103 participants from 16 countries in three continents: Africa (Kenya, Ethiopia, Ghana, Uganda, South Africa, Malawi, Mozambique, and Lesotho), Asia (Nepal, Bangladesh, India, and Iran) and the Americas (Brazil, Haiti, Bolivia and Vietnam). There was a statistically significant association between water insecurity and CMD symptoms. Nine studies reported a continuous outcome (5,248 participants): overall standardized mean difference (SMD = 1.38; 95% CI = 0.88, 1.87). Five studies reported a binary outcome (5,776 participants): odds ratio 5.03; 95% CI = 2.26, 11.18. There was a statistically significant association between inadequate sanitation and CMD symptoms (7415 participants), overall SMD = 5.36; 95% CI = 2.51, 8.20. LIMITATIONS: Most of the included studies were cross-sectional which were unable to examine temporal relationships. CONCLUSIONS: Water insecurity and inadequate sanitation contribute to poorer mental health globally. IMPLICATIONS OF KEY FINDINGS: Interventions to provide basic water, sanitation and psychosocial support, could substantially contribute to reducing the burden of CMD alongside other health and social benefits. TRIAL REGISTRATION: PROSPERO registration number: CRD42022322528.