RD Laing wrote a lot about this topic a long time ago. He has had cycles of being revered and reviled.

There was one flu epidemic in the fifties that seemed causally related to an increase in schizophrenia when mothers in the second trimester got that flu, their offspring was more likely to be schizophrenic. Subsequent research didn't find a causal connection with any other flu epidemics. Some researches are very much of the opinion that toxoplasmosis gondi infections have some bearing on mental illness. I brought up these biological, pathogen related theories because I wanted to make the point an increase in mental illness might have non-social causes, if an increase has occurred.

I think my schizophrenia/schizoaffective situation had some indicators in childhood. I also discovered I had an encephalitic (brain swelling) reaction to one of my childhood immunizations. I don't believe immunizations cause autism. The causality of my infant brain swelling might have not been the immunization, could have been an unrelated infection only connected to immunization by proximity in time. Anyways I think my MI has a strong biological basis.

However my being kept in a small Catholic grade school with faculty and students who had their own mental health situations, to spite the fact they were ill equipped to deal with me was something that I'm sure worsened my MI.

So even if most MIs are biological, I firmly believe situations like a MI person ending up in jail rather than getting a needed hospitalization really worsen a lot of people's MIs.

And I do think sometimes like my MI is mostly psychogenic rather than biological. I think its good to be multi-model about mental illnesses because in the average clinical situation no physical causes were determined. Our diagnosis usually came about by eliminating a few causes through an exam and some lab tests, and then figuring what mental illness our symptoms most matched. In a research setting more advanced genetic and metabolic markers might have been considered and there could have even been advance brain imaging like SPECT or PET scan, but that's rare.

I'm of a model that is biological, social, and psychological. I believe looking at societal causes is very worthwhile and in some people's cases I believe societal causes are primary.