There are no tests or biological measures that can assist in making the diagnosis of
schizoaffective disorder. Whether schizoaffe ctive disorder differs from schizophrenia
with regard to associated features such as structural or function al brain abnormalities,
cognitive deficits, or geneti c risk factors is not clear.
Prevalence
Schizoaffective disorder appe ars to be about one-third as common as schizophrenia. Life-
time prevalence of schizoaffective disorder  is estimated to be 0.3%. The incidence of