What is the primary difference between schizophrenia and schizoaffective disorder?

• A. Schizophrenia involves psychotic symptoms with or without mood symptoms; schizoaffective requires prominent mood symptoms concurrent with psychotic symptoms plus periods of psychosis without mood symptoms.
• B. Schizophrenia involves mania.
• C. Schizoaffective has no psychotic symptoms.
• D. Schizophrenia always includes mood symptoms.

Answer: (A)

The key idea is how mood symptoms relate to psychotic symptoms over the course of the illness. Schizophrenia centers on psychosis; mood symptoms, if they occur, are not a defining, persistent feature. Schizoaffective disorder combines psychosis with a major mood disorder, and there must be periods of psychosis without mood symptoms as well.

In schizoaffective disorder, there is a mood episode (depressive or manic) that occurs concurrently with psychotic symptoms, and outside of those mood periods there are still psychotic symptoms present for some time. This means you see psychosis both with mood symptoms and by itself, across the illness. That pattern distinguishes it from schizophrenia, where mood symptoms are not prominent or persistent enough to define the illness, and from other conditions that would lack psychotic symptoms altogether.

Mood symptoms in schizoaffective can be depressive or manic, but the defining feature is their combination with psychosis plus phases of psychosis without mood disturbance. This is why the described option best captures the difference.