Medication-induced somnambulism in a patient with schizoaffective disorder

A 39-year-old man with schizoaffective disorder experienced somnambulism only when taking a combination of lithium carbonate, chlorpromazine, triazolam, and benztropine. This was confirmed in the sleep laboratory. The sleepwalking occurred during Stage 2 sleep; the sleep record showed a marked paucity of REM sleep. The patient's brother had had one episode of somnambulism, also following exposure to a substance affecting the CNS. A role for CNS-active medications in triggering some pathologic sleep phenomena in predisposed individuals is hypothesized. Medications with central anticholinergic activity may be particularly important.