>>13474103well look the truth is that people who are diagnosed with narcissistic personality disorder actually are high functioning autistic and have inadvertently developed a sort of complex in their ego that leads to narcissistic behavior. Just to counter your example, but do not take this to mean every personality disorder is secretly autism. Rather there is a more specific underlying problem that causes certain symptoms to be presented.
There are certain ways the brain will improperly function and many of these quirks are objectively traced to chemical imbalances with serotonin and dopamine. Its extremely probably that most mental illness is also tied to chemicals in the brain, and those who aren't positively affected by medication are psychosomatic/behaviorally deficient, or novel though very unlikely.
Some psychologists and psychiatrists don't give a fuck about their patents but that doesn't mean there is a grand conspiracy in the works. What is actually happening is the science is getting better at understanding whats happening in the brain.