Schizophrenia occurs in all societies, and one in 100 people will be diagnosed with schizophrenia at some time in their lives. It is the most common among all the psychotic illnesses. Most researchers and clinicians agree that schizophrenia is a biopsychosocial disorder.

This means that syndrome of schizophrenia has a biological basis, and that in patients who eventually develop the illness this biological predisposition has interacted with psychosocial stressors.