Schizophrenia is an illness of the brain that causes certain characteristic, abnormal experiences and behaviors. There are several types of schizophrenia that involve different clusters of symptoms. It is possible that slightly different disease processes are involved in the different types of schizophrenia. However, most researchers believe that schizophrenia is a single disease which can have different effects depending on which brain regions are most effected.
Researchers do not yet know exactly what causes some people to develop schizophrenia. There is a very strong genetic component to schizophrenia. However, genes alone do not completely explain the illness.
Most scientists believe that genes don’t cause schizophrenia directly, but do make a person vulnerable to developing the disease. Scientists are studying many possible factors that might cause a person with a genetic predisposition to develop schizophrenia.