A mental illness is not caused by bad parenting and is not a character weakness or flaw. Schizophrenia Schizophrenia is one of the most serious and disabling of the mental illnesses. It affects approximately one person in a hundred, men and women about equally. The onset is usually in the late teens or early twenties. They are also called mood disorders.
Many cases go unrecognized and untreated.
Without proper medical treatment, such persons experience repeated or continuous periods of illness and perhaps hospitalization. About six percent of the population suffers from an affective disorder. These disorders are a major cause of suicide. The causes of mental illnesses are not as well understood as other physical diseases, but research is providing useful information on the functioning of neurotransmitters and brain chemistry that is involved. Heredity may be a factor as it is in diabetes and cancer.