Which condition is characterized by Major Depressive Disorder (MDD) or mania with symptoms from Criterion A of schizophrenia?

The condition characterized by Major Depressive Disorder (MDD) or mania along with symptoms from Criterion A of schizophrenia is known as Schizoaffective Disorder. This disorder uniquely combines elements from both mood disorders and schizophrenia, where an individual experiences significant mood episodes (either depressive or manic) in conjunction with psychotic symptoms such as hallucinations or delusions (included in Criterion A).

In Schizoaffective Disorder, the mood symptoms and psychotic features occur simultaneously, or at least the psychotic symptoms occur in the absence of mood symptoms for a significant portion of the illness. This differentiates it from conditions like Bipolar Disorder, which primarily involves mood symptoms without the persistent psychotic component. Similarly, Major Depressive Disorder and Schizophreniform Disorder lack the full criteria overlap regarding mood disorders and psychotic episodes required for a diagnosis of Schizoaffective Disorder. Therefore, the combination of both mood and psychotic symptoms is what establishes the defining characteristics of Schizoaffective Disorder as the correct choice.