A study says morning grogginess is more debilitating than sleep deprivation. Researchers at the University of Colorado at Boulder and Boston's Brigham and Women's Hospital say the effects of sleep inertia are as bad or worse than being legally drunk.

The findings, published in the Jan. 11 issue of the Journal of the American Medical Association, show that people who awaken after eight hours of sound sleep have more impaired thinking and memory skills than after being deprived of sleep for more than 24 hours.

Lead study author Kenneth Wright said test subjects had diminished short-term memory, counting skills and cognitive abilities during the groggy period upon awakening known as sleep inertia.

Researchers found subjects exhibited the most severe impairments from sleep inertia within the first three minutes after awakening. The most severe effects generally dissipated within the first 10 minutes, although its effects are often detectable for up to two hours.

Wright said the study has implications for medical professionals who are often called on to tend patients in crisis on a moment's notice, often at odd hours.

Copyright 2006 by United Press International