Aside from the obvious physical changes that occur as we age, changes to the patterns of our sleep, known as sleep architecture, are part of the normal aging process. Slow wave sleep (SWS), referred to as deep sleep, is greatest in childhood, remains high into young adulthood, and progressively decreases with age. Furthermore, young healthy adults have demonstrated greater vulnerability to acute sleep deprivation than older adults. These two findings raises the question whether there is a reduction in sleep need as we age and/or are older adults less capable of making the transition to SWS. A study published in Nature by researchers at Brigham and Women’s Hospital and Harvard Medical School investigated whether younger adults are more susceptible to chronic sleep disruption combined with irregular sleep timing.
Healthy young adults (mean age: 22 years-old) and older adults (mean age: 59 years-old) were recruited to participate in a 3-week chronic sleep disruption forced desynchrony schedule. No differences were observed in subjective sleepiness, as both age groups reported increased sleepiness the longer they stayed awake. While the subjective sleepiness measure leveled off for both age groups, objective sleepiness measures continued to worsen. This suggests, regardless of age, people are poor judges of how exhausted they are. Further, young adults exhibited significantly poorer attention and a higher likelihood to fall asleep than older adults following chronic sleep loss. Young adults are more biologically susceptible to sleep loss while older adults are more capable of dealing with it. This supports the hypothesis that, under chronic sleep restriction, older adults have a reduced need for sleep. Overall, young adults who sacrifice sleep due to social or work factors are jeopardizing their health.