By Renée Grinnell

A sudden decline in attention, focus, cognition, and perception developing over hours or days. Not to be confused with dementia.

Example: An elderly alcoholic man who was asymptomatic yesterday mumbles, picks at invisible objects, seems intensely fearful, and misidentifies you as his relative.

    Last reviewed: By John M. Grohol, Psy.D. on 11 Oct 2008