A long-term mental disorder of a type involving a breakdown in the relation between thought, emotion, and behavior, leading to faulty perception, inappropriate actions and feelings, withdrawal from reality and personal relationships into fantasy and delusion, and a sense of mental fragmentation. - Google
Schizophrenia is a serious mental disease in which multiple thought processes in the person's mind seem like there's another person (or more) in there, often giving bizarre warnings or making bizarre threats. Schizophrenia also usually includes heightened paranoia and a lack of empathy for other people. It is NOT a "split personality" like you sometimes hear in old movies or old TV shows. There are several medications to treat schizophrenia but not everyone responds the same and not everyone can get well.