Anticholinergic medications even in therapeutic range can cause recurrence of psychosis

Anticholinergic drugs are commonly used in psychiatry to attenuate antipsychotic induced extrapyramidal syndrome (EPS). Psychosis as a side effect is generally explained under the rubric of anticholinergic toxicity or induced delirium. Anticholinergic induced worsening of psychosis in patients with normal cognition is extremely rare in literature. Here, we arepresenting a case of young female who was prescribed with multiple anticholinergics to reduce EPS, and each time had worsening of psychosis with intact cognition. We then discussed the possible neurobiological explanation with special reference to muscarinic hypothesis of schizophrenia.