They have no certainty, they make it up as they go along. It keeps them employed. Drugs, drug companies and big business interests keep them afloat, along with government grants. New York state recently approved experimentation with out consent upon those institutionalized there. This demand is in the future of a world that wishes to continue on as civilized.
Psychiatry has no interest in civilization.
IT ISN'T for benefit. It is harmful spiritually, mentally to any and all. It takes away personal power and knowledge of a personal, mental and spiritual nature. Psychiatry does not have the answers to questions of the mind and life. And it is evil.