Parasomnias, Violence and the Law

Abstract

In this review, we trace the parallel development of scientific understanding of parasomnias and the jurisprudence of violent behavior during sleep. Before sleep physiology was studied, it was generally self-evident that sleeping persons would not be criminally responsible. Though the problem of malingering was acknowledged in early American forensic psychiatry, the defendant with sleepwalking or sleep drunkenness was treated leniently. Over the past half century, sleep physiology has been examined and there is a developing nomenclature for sleep disorders. Though there is no clear-cut correlation between violence and sleep, several parasomnias have been implicated. We discuss contemporary concepts of parasomnias and suggest how expert witnesses might apply this knowledge to the difficult matter of assessing criminal intent and responsibility.