Schizoaffective disorder is a thought disorder that includes both psychotic features (as seen in schizophrenia), and mood symptoms that may be either depressive or manic in presentation. The psychotic and mood symptoms may occur together or at different times. Schizoaffective disorder is diagnosed in fewer people than is schizophrenia: Approximately 1 percent of the population worldwide will be diagnosed with schizophrenia; 0.3 percent with schizoaffective disorder. Because the prevalence of schizoaffective disorder is low and because it includes both mood and psychotic features, the disorder can be difficult to diagnose.
While at least two primary criteria for schizophrenia must be present, an important distinction is that people with schizoaffective disorder are more functional in terms of self-care and in their ability to interact with others.