Last reviewed 01/2018
This is a diagnosis of exclusion.
The first step is the exclusion of organic causes e.g. temporal-lobe epilepsy, metabolic disturbances, toxic substances.
Differentiation from other psychiatric disorders e.g. an affective disorder with psychotic symptoms must be made - in this case a patient with schizophrenia may have mood disturbances but, if they occur, they tend to occur recurrently, and the episodes of psychosis are more enduring than the mood disturbances.
The American Psychiatric Association has outlined a list of diagnostic criteria for schizophrenia. These are outlined in the menu item.