Age and the Effects of Sleep Deprivation

By Dr. Gregg D. Jacobs

Although sleep deprivation can have significant adverse effects on mood and neurobehavioral functioning, the effects of sleep deprivation depend upon the person, the type of sleep loss (partial or total sleep loss) and for how long, whether recovery sleep is allowed to occur, and the circumstances under which sleep loss takes place. Furthermore, recent research has documented that there is significant individual variability in response to sleep loss: some individuals show little effect while others show significant adverse effects.

A recent study published in the Journal of Sleep Research (13:105-13, 2004) by Dr. Pierre Phillip and colleagues investigated the effects of age on neurobehavioral functioning after sleep loss using measures of reaction time. The majority of research on the effects of sleep loss has involved young, healthy subjects (typically college students), who show faster reaction times than older subjects when well-rested. These investigators studied the effects of one night of total sleep deprivation on reaction time in two groups of subjects: healthy males with a mean age of 22 and healthy older males with a mean age of 58, all of whom were normal sleepers.

The researchers found that, when well-rested, older subjects had slower reaction times than younger subjects. However, this finding was reversed after a night of total sleep deprivation: younger subjects had slower reaction times than older subjects and therefore were more impaired as a consequence of sleep deprivation. In fact, the neurobehavioral functioning of the older adults after sleep deprivation was not significantly altered.

These findings are important for several reasons. First, they suggest that younger adults are more sensitive to the effects of sleep loss, perhaps due to differences in sleep need or sleep drive. Second, these findings emphasize the need for caution when interpreting the results of sleep deprivation studies since these typically involve young subjects. The present findings suggest that the effects of sleep deprivation may not be as significant in older adults. In order to develop a more accurate picture of how sleep deprivation affects neurobehavioral functioning, future studies need to include older adults, including those age 60 or above.

Once again, the effects of sleep deprivation are not a "one size fits all" phenomenon. Our present understanding of the effects of sleep loss, based primarily on studies of young adults, may not be generalizeable to middle age adults or the elderly.