Final answer:
Schizoaffective disorder is characterized by psychotic symptoms that occur with and without mood symptoms, whereas in bipolar disorder, psychotic symptoms only occur during mood episodes. Absence of mood symptoms during periods of psychosis is a key factor in differentiating schizoaffective disorder from bipolar disorder.
Step-by-step explanation:
The differentiation between schizoaffective disorder and bipolar disorder can be quite complex due to the overlap of symptoms related to mood and psychosis. To distinguish schizoaffective disorder from bipolar disorder, it is critical to look at the presence or absence of certain features:
Schizoaffective disorder is diagnosed when a person experiences psychotic symptoms (such as hallucinations or delusions) concurrent with mood disorder symptoms (which may include manic or depressive episodes), but also has periods of psychosis without mood symptoms. This is a key differentiator from bipolar disorder, where mood episodes may also include psychotic features, but the psychotic symptoms are not present when mood symptoms are absent.
Bipolar disorder is characterized by alternating episodes of mania and depression, and while psychotic symptoms can occur, they happen exclusively during these mood episodes. Hence, the correct answer to the question is the option indicating the absence of mood symptoms in schizoaffective disorder during certain phases of the illness.