It may be that higher levels of inequality have increased the incidence of poor mental wellbeing in the community. A recent book suggests a causal mechanism from one to the other.

International research shows that there is a socioeconomic status (or class) gradient, in which those with low SES experience higher morbidity from respiratory and cardiovascular diseases, ulcers, rheumatoid disorders, a number of cancers, psychiatric diseases, dementia and so on.