Which cluster of symptoms constitutes delirium in antipsychotic-induced anticholinergic toxicity?

• A. Agitation, confusion, disorientation, visual hallucinations, tachycardia
• B. Depression and anhedonia
• C. Nausea and vomiting
• D. Dizziness only

Answer: (A)

Delirium is an acute, fluctuating disturbance of attention and awareness with cognitive and perceptual disruption. In anticholinergic toxicity from antipsychotics, central muscarinic blockade triggers this sudden brain dysfunction, so you see rapid onset of confusion and agitation, plus disorientation and perceptual changes such as visual hallucinations. Tachycardia is a common autonomic sign in this context, reflecting the anticholinergic effect on the autonomic nervous system. The combination of agitation, confusion, disorientation, visual hallucinations, and tachycardia best fits delirium due to anticholinergic toxicity.

Mood-focused symptoms like depression with anhedonia are not delirium; nausea and vomiting are GI/autonomic symptoms without the cognitive disruption; dizziness alone is nonspecific and does not capture the acute cognitive-time course of delirium.