The biggest problem with mental illness treatment is its mostly guess work. Physical health is still some guess work in areas but have overall better test and feed back methods.
In mental health some new "big discovery " is made and the "experts " decide to jump on board and announce this is the best thing for people that are mentally ill. There is no way to prove them wrong because they say they are the experts and there is no real study that can show if they are right untill it's been years. Then the harm starts to come out and all you get is a woops guess that didn't work like we thought at best.