What is a required DSM 5 criterion for diagnosing schizoaffective disorder?

For diagnosing schizoaffective disorder, a key criterion involves the presence of symptoms of a major mood episode occurring for the majority of the total duration of the illness. This means that the individual's mood symptoms—be it mania or depression—must be prominent and significantly influence the clinical picture throughout the course of the illness.

This criterion is critical because schizoaffective disorder is characterized by features of both schizophrenia and mood disorders. The emphasis on mood symptoms being predominant establishes a clear distinction from other psychotic disorders, as patients exhibit both the hallmark psychotic features of schizophrenia alongside prominent mood disturbances.

It is important to note that diagnosing schizoaffective disorder also relies on the presence of certain symptoms, such as delusions or hallucinations, which occur independently of mood episodes. However, the defining factor that contributes to its classification as schizoaffective rather than strictly a mood disorder or schizophrenia is the majority presence of mood symptoms over time. This particular criterion helps delineate the nuances of the disorder, guiding clinicians in arriving at an accurate diagnosis and subsequent treatment strategy.