What symptom is common in both schizophrenia and schizoaffective disorder?

Hallucinations are a shared symptom in both schizophrenia and schizoaffective disorder, making this answer accurate. In schizophrenia, hallucinations, particularly auditory ones, are a core component of the disorder, often leading to significant impairment in functioning and a distorted perception of reality. Similarly, schizoaffective disorder also includes hallucinations, but it is characterized by the presence of mood episodes (depressive or manic) alongside symptoms of schizophrenia.

While delusions, anxiety, and disorganized speech can be present in both disorders, they are not universally applicable to both conditions. Delusions, for instance, are prevalent in schizophrenia, but the nature and context of their occurrence may vary when co-occurring with mood-related episodes in schizoaffective disorder. Anxiety is more broadly associated with various mental health disorders and is not specific to these two. Disorganized speech can also appear in both disorders, but it is more commonly emphasized in the context of schizophrenia. Therefore, hallucinations stand out as a definitive commonality, highlighting an important feature shared by both diagnoses.