A 37-year-old man presents for evaluation. He has had persecutory delusions and hallucinations for seven months. He is admitted to the hospital for evaluation of acute psychosis. He has no history of a mood or anxiety disorder, does not smoke or drink alcohol, and does not use drugs. During an evening evaluation, concern for catatonia arises. Of the following, which may be a diagnostic characteristic of his current presentation?
Distractibility
Echolalia
Flight of ideas
Increased talkativeness