schizophrenia
"My son had severe acute psychosis and possible diagnosis of schizophrenia at age 17.  Risperdal (Risperidone) brought him back to his normal self, for the most part.  He has put on weight (2 trouser sizes bigger) and he is inclined to rock back and forth a little, when seated.  He is slightly less motivated and says he doesn't retain information as he used to at school.  This may be improved by adjusting the dose.  But this medicine gave me my son back and seems well-tolerated by him.  The psychosis is completely gone."