The world of medicine wasn't as advanced as it is today. There have been many different ways of dealing with diseases and sicknesses. But when it was about mental problems, it was probably more difficult than the others because it's not seen like an open wound or a runny nose. Perhaps one of the most brutal methods to treat the mentally ill was hydrotherapy. You can be glad that it's not used anymore to treat patients.
A Torture Method Developed To Treat Patients In Mental Hospitals: Hydrotherapy