Mood episodes are prominent and recur throughout the illness (unlike schizophrenia)
Assess the longitudinal course of the illness to see if there are at least 2 weeks of psychotic symptoms in the absence of a mood episode
Major depressive or manic episode concurrent with symptoms of schizophrenia
Lifetime history of delusions/hallucinations for >= 2 weeks in the absence of a major depressive or manic episode
Mood episodes are prominent and recur throughout the illness
Not due to substances or another medical condition
Schizoaffective disorder can be differentiated from schizophrenia and bipolar disorder by assessing the relationship of mood and psychotic symptoms over the course of the illness. Mood symptoms in schizophrenia are present for relatively brief periods of time. In bipolar I, psychotic symptoms occur exclusively during manic or depressive episodes.
Is the patient's mood stable?
Are there psychotic symptoms happening?