Mental distress and resource insecurity in the Kingdom of Tonga following the 2022 volcanic eruption: Associations of water and food insecurity with mental distress.

Background: Water and food insecurity can harm mental health; all three may in turn be exacerbated by humanitarian crises. The linkages between food insecurity, water insecurity, and mental health are gaining attention but have not been investigated after a natural disaster.

Objective: To investigate the associations between food insecurity, water insecurity and mental distress, and how these relationships may differ between women and men, in the aftermath of the 15 January 2022 volcanic eruption in the Kingdom of Tonga.

Design: Secondary analysis of nationally representative cross-sectional data from the Equality Insights Rapid survey collected 4-5 months after the eruption, between 17 May and 30 June 2022.

Participants/setting: This study analyzed individual data on food insecurity, water insecurity, mental distress, and sociodemographic covariates collected from women and men ≥18 years old (n=6,650). Participants were eligible if they had been a member of the same household since 2021 and were able to communicate independently on the phone in Tongan or English.

Main Outcome Measures: Mental distress over the past 4 weeks, measured using the 6-item Kessler Screening Scale (K6).

Statistical Analyses Performed: Multivariable negative binomial and logistic regression models were used to test how food and water insecurity relate to both continuous and dichotomized measures of mental distress, respectively. Food insecurity was measured using the 8-item Food Insecurity Experience Scale (FIES) and water insecurity was measured using the abbreviated Individual Water Insecurity Experiences (IWISE-4) Scale. Models were estimated separately for women and men and adjusted for age, marital status, number of minors and adults in the household, educational attainment, employment status, household wealth quintile, and urbanicity.

Results: Water insecurity was independently associated with higher odds of experiencing moderate-to-severe mental distress among women (OR=1.66, 95% CI=1.29-2.14) and men (OR=1.40, 95% CI=1.09-1.80) when adjusting for food insecurity. Those experiencing concurrent water and food insecurity were at the highest risk of experiencing mental distress compared to those experiencing only one insecurity or neither. The strength of associations was similar among women and men.

Conclusions: The deleterious relationship between concurrent water and food insecurity and mental distress highlights the importance of addressing both insecurities and helping those experiencing both insecurities, particularly in the aftermath of humanitarian crises.