I came across two studies today focused on stress and loneliness and the negative health affects they can bring.
The first study, via Useful Science, concluded through epidemiological means that socially-related stress doubled (sometimes tripled) the risk of death in middle-aged adults.
The second study, via Ergo Log, put a physiological conclusion behind what we already know: lonely people live less long than those with many social contacts. Why?: loneliness increases the negative inflammatory processes that come about during acute and chronic states of stress.
The literature is growing here. Stress kills, often more rapidly than anything else, which is why we have to prioritize our own mental health alongside physical health.