Making waves: Mental health impacts of inadequate drinking water services - From sidenote to research focus.

The paramount significance of the harmful impacts of poor drinking water services on physical health have been recognized for decades. Besides, over the past twenty years, an additional body of literature on their negative mental health impacts has emerged. With this brief review, we summarise the findings of the scholarship to advance addressing overall health (physical, mental, and social) in the water sector. We furthermore review the key policy documents of this field with a focus on mental health aspects and give recommendations for practitioners and decision-makers on addressing mental health in water service delivery. We reviewed the existing published works (42) assessing psychological impacts of deficient drinking water services in low-income settings. We then identified and compared the different mechanisms causing negative mental health outcomes described in them. For these purposes, we used a water insecurity experience -model and the vulnerability-stress model of clinical psychology. Next, we probed key international and national guiding documents of the water sector to analyse how mental health issues resulting from poor services are addressed today. We found that according to the literature, poor quality and quantity of water was predictably one of the most important psychosocial stressors to users. Surprisingly, however, various kinds of water-service-related inequalities (e.g. between genders, communities or socio-economic groups) showed up as equally significant stressors. Our analysis with the vulnerability-stress model furthermore indicates that insufficient drinking water services may predispose to common mental disorders particularly through external stress. Existing field guidelines have evolved to highlight the values of non-discrimination and participation, whilst mental health aspects remain ignored. This should not be the case. Therefore, practices for addressing mental health effectively in documentation and water service development should be further researched. But already in the light of the existing literature, we urge stakeholders to focus more on the negative mental health impacts of unequal service provision for users and nearby people left without improved services.