This is what I previously wrote about the treatment of mental illness in the USA in TTL, slightly edited:
By 2022, one major difference in the USA in TTL from the USA in our world is that no equivalent of the Community Mental Health Act was passed, meaning that there has not been a widespread move towards deinstitutionalization. In the USA, the Bureau of Asylums (BoA) of the Department of Health oversees a national network of federally-funded mental health facilities, including hospitals.
The US state-supported mental health system is not dissimilar from analogous systems in other countries, although funding levels and the overall quality of care varies, depending on the country in question. In the vast majority of countries, including in all of the great powers, there is the expectation that the state should assume full responsibility for those in need of mental health-related treatments.