Hi, A Friend I Care For Was Put On Anti-psychotic

Hi, a friend I care for was put on anti-psychotic medication at a time that he was taken by police to hospital due to having drug induced psychosis. (One of countless incidences.) I understand the usefulness of the anti-psychotic drug to block the excessive dopamine cause by the drug use at the time, resulting in the psychosis. However, that occurred almost 3 years ago and he is still being prescribed the anti-psychotic even though he no longer drinks or drugs. So he now suffers from extreme fatigue (and other low dopamine symptoms) and lays in bed 24 hours a day, asleep at least 20 hours per day. He says that his doctor says he has to stay of the medication for the rest of his life. He is only 53 years old and has two children. What can you suggest please?