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Naps Boost Cognitive Performance in Seniors

Posted 22nd February 2011

Insomnia is a common complaint among elderly individuals. With aging, there is a pattern of decreased number of total sleep time and reduced time in deep sleep. Deep sleep is considered restorative sleep, an important component of feeling rested and alert the following day.

Sleep hygiene recommendations commonly warn against napping during the day time as it is felt to reduce the quantity and quality of sleep at night. However, many individuals report that napping during the day is helpful for them in getting sufficient sleep on a regular basis. Now there is some limited data that supports a role for regular napping for increasing total sleep time as well as some parameters of cognitive function.

Campbell and colleagues studied the effects of a month-long napping regimen in a series of individuals between the ages of 50 and 88 years of age. Key elements of the research design included:

Inclusion criteria: age over 50 with self-reported good physical health, subjective insomnia complaints allowed but subjects had to score less than 5 on the Pittsburgh Sleep Quality Index and 2 or less on the sleep latency item from this scale, no regular sleeping medications, not taking psychotropic meds or other medications known to affect sleep, minor but not major medical problems, no periodic limb movements on baseline polysomnography
Study variables/procedures: Sleep diaries and actigraphy at home 1 to 2 weeks before baseline laboratory examination, 3 consecutive nights and 2 days spent in sleep lab with polysomnography and neuropsychological testing including a test of logical reasoning, mathematical processing, letter memory search and reaction time test.
Intervention: Randomization to either directed 45 minute nap or 2 hour nap, at least 5 times per week but recommended daily, to be completed in single setting before 6 pm to include daily sleep logs
Outcome measures: Subjects returned for sleep lab evaluation for 2 nights at 2 and 4 weeks after randomization

The key elements of the outcome of the study:

Napping did not change any of the night time sleep parameter: sleep onset latency, sleep efficiency or total nocturnal sleep time
In 24 hour assessment of sleep both groups increased their total sleep time although as expected the long nap group had a longer total sleep time than the short nap group
Neuropsychological performance improved in both groups at 2 and 4 weeks on three of the four neuropsychological measures (all but reaction time). The improvement was not statistically significant but the longer nap group tended to show greater improvement
Adherence to recommended nap assignment: (9/11) in the short nap group met defined adherence while 5/10 in the long nap group met adherence—this difference was not significant

Although a small sample study, this research finding seems allay some concerns about a regular nap regimen for those over age 55 years of age. There does not appear to be evidence that napping impairs nocturnal sleep in duration or quality. The added sleep during the day with a nap in this study was accompanied by improvement in some elements of cognitive function. This improvement appeared to continue through 4 weeks and may not have reached its peak by that time. The authors note that none of the subjects were regular nappers before entering the study.

So the take home message from the study is that for those 50 or older if you are taking a daily nap and feel it helps you, keep doing it. If you are not taking a daily nap and would like to consider adding one, it does not appear to be a risk for disrupting nocturnal sleep and you may get some cognitive boost from a daily napping regimen.

Photo of napping kittens courtesy of Wikepedia Commons author Tilman Piesk.

Campbell, S., Stanchina, M., Schlang, J., & Murphy, P. (2011). Effects of a Month-Long Napping Regimen in Older Individuals Journal of the American Geriatrics Society, 59 (2), 224-232 DOI: 10.1111/j.1532-5415.2010.03264.x.