A few years ago I caught a reference to a book originally published in 1956 and updated in the 1970's. My local state university's science library has a copy. It talked about the biochemistry of the organisms' response to stress, and the stress response's role in many "mental" conditions. Selye was the author iirc.
A few years ago some researchers figured out that psychotic patients don't make enough cortisol in the morning [0], as Selye's book might've indicated decades earlier.
20 years ago some scientists figured out the SSRIs help some people by influencing the neurosteroids [1].
The tragedy of our approach to mental health is that many/most patients deteriorate due to the FDA-approved palliative drug cocktails their doctors think are appropriate, instead of getting physiologic interventions. The widespread use of anti-dopamine drugs ("anti-psychotics") is a crime against science.
[0] https://psychcentral.com/news/2016/06/04/low-morning-cortiso...
[1] https://www.ucsf.edu/news/1999/11/5059/scientists-identify-n...
Stress/cortisol adversely affects young people's thinking ability: https://www.scientificamerican.com/article/ldquo-stress-horm...
study on the HPA and psychiatric conditions: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3707958/