Schizophrenia is a chronic and severe mental disorder, which affects the neuropsychiatry system, that can be characterized by episodes in which the patient is unable to distinguish between real and unreal experiences. Subtypes of schizophrenia include paranoid schizophrenia, disorganized schizophrenia, catatonic schizophrenia, undifferentiated schizophrenia, and residual schizophrenia.