Psychiatric considerations in patients with decreased levels of consciousness.

When patients present to the emergency department with changes in behavior and levels of consciousness, psychiatric causes often move to the top of the list of diagnostic considerations. It is important to thoroughly assess such patients for medical causes. Although it is not common for primary psychiatric conditions to present with altered levels of consciousness, severe cases may present in this fashion. Altered mental states may also be caused by adverse reactions to psychiatric medications. In this article, the authors review some of the psychiatric causes of decreased levels of consciousness, as well as certain adverse drug reactions to psychotropic medications. Copyright 2010 Elsevier Inc. All rights reserved.