Somnambulism induced by quetiapine: two case reports and a review of the literature.

Somnambulism, a previously unreported side effect of quetiapine, is described in two cases. Both cases involved individuals who had no prior or family history of somnambulism and had attention-deficit/hyperactivity disorder. The possible significance of this will also be discussed. Somnambulism is a common parasomnia that reflects an impairment in the normal mechanisms of arousal from sleep in which motor behaviors are activated without full consciousness. Motor behaviors are initiated during deep non-rapid eye movement or slow-wave sleep (stages 3-4), and may be limited to relatively simple manifestations, such as sitting up, fumbling with objects or bedclothes, or mumbling.