[biophysboy]

>Recent meta-analyses examining 2.2 million individuals across 90 cohort studies reveal that social isolation and loneliness trigger measurable biological cascades comparable to traditional disease risk factors.

Its frustrating, because cohort study experimental designs like these can in principle chip away at reverse causality (i.e. observe loneliness exposure before a cardiovascular disease prognosis, compare difference-in-difference between treatment/control), but the meta-analysis doesnt clearly state whether this constraint was applied. But even a study like this would have issues with medical participation, so that would need to be controlled, preferably with a prospective design.

[lanstin]

Having a spouse or friend nag you into going to the doctor is undoubtably a part of the effect, both for the practical side and for the feeling that someone would care if you were ill. (Assuming this is what you mean by "issues with medical participation.")