And then there’s the related issue that our evening and night time use of screens to text, email, watch Netflicks, game, etc. affects our sleep. This is a major health issue, especially for students, and there is a urgent need for good sleep hygiene and screen habits.

According to the International Journal of Epidemiology  (Ferrie, Kumari, Salo, Singh-Manoux & Kivimaki, 2011), “Population studies show that sleep deprivation and disorders affect many more people worldwide than previously thought” (p. 1432) such as insomnia: 30% of adults report “some insomnia problems over the past year” (p. 1432) and chronic short sleep. According to Carpenter (2013) ( see her article on the American Psychological Association [APA] website), the American Centre for Disease Control and Prevention finds that a quarter of American adults don’t get enough sleep (7.5 to 8 hours a night) at least half of the time, and for adolescents, who should average a bit over 9 hours a night, a quarter get no more than 6.5 hours. At that rate, they are chronically sleep deprived. And the typical “phase-delay shift” that happens in adolescence tends to worsen their sleep hours. (They get to sleep later, but still have to get up early to go to school).

What is happening to our sleep? Partly it is our work and play habits, with artificial lights allowing us to stay up late, sacrificing sleep hours to these compelling on-line activities. And partly it is the physiological effects of the light and the screens on our circadian rhythms. And it is likely that with screen use up to bedtime, this epidemic of sleep problems will increase.

As Ferrie et al. (2011) note, “the ‘24/7’ society involving round-the-clock activities and increasing night-time use of TV, internet and mobile phones means adequate uninterrupted sleep may become increasingly compromised” (p. 1432). They cite research that we are experiencing a decline in sleep time of approximately “18 min per night over the past 30 years”. Sleep hours are sacrificed as people stay awake to email or text, watch Netflicks, or game, even though they still have to get up early the next day for work or school. Roenneberg (as cited in Carpenter, 2013) calls this a “social jet lag” – our circadian rhythms, the “body’s internal clock”, is out of sync with the social clock of daytime work and school schedules.

And just as with jet lag, when we habitually short sleep, we may have a hard time getting to sleep (insomnia, or disrupted sleep) when we do finally go to bed. For all these reasons, sleeping less than 6 hours a night is now more common, while for most of us, 8 hours sleep is optimal for our health and well-being, and for adequate daytime functioning.

Partly this is the physiological response of our circadian rhythms, the body’s biological clock, which runs our hormonal systems to govern our sleep-wake cycles, hormone release, digestion, etc. (National Institute of General Medical Sciences). Light levels in our environment are signals that provoke the brain to produce melatonin, which makes us sleepy. So artificial light and mobile devices mess with our circadian rhythms and the normal production of melatonin, and late night studying or shift work among workers and students in artificial light sources disrupt the usual signals from our body and the environment that help us sleep.

And when we try to catch up on the missed sleep on the weekend, as students often do, the circadian rhythms are disrupted again. Roenneburg (as cited in Carpenter, 2013) called the very common habit of staying up too late on week nights and sleeping later on weekends, then back to an early start on Mondays (69% of respondents in his study of 65,000 respondents) to be like traveling across three time zones every Friday and back again on Monday morning.

And to add to evening work in artificial light, our increasing use of screens with blue light wavelengths up until bedtime has made our sleep problems much worse, further altering our circadian rhythms and sleep-wake cycles (NIH, 2017).

Bradford (2016) explains that fluorescent and LED light create sleep problems not only because they are artificial light impacting our circadian rhythms when we would otherwise be physiologically preparing to sleep, but also because they produce blue light. “Blue light wavelengths produced by electronics and overhead lights boost attention, reaction times and mood, according to Harvard Medical School.” This doesn’t make for an optimal sleep environment. “Exposure to blue light suppresses the production of melatonin more than any other type of light …. because the body is more sensitive to this type of light” (Bradford, 2016, para 7).

And we now understand through experimental evidence the serious effect sleep problems can have on our health and daytime functioning. We know that sleep significantly helps learning, the consolidation of what we have learned in our memory, emotional balance and self-regulation (Shakespeare was right) and creativity. And sufficient sleep is necessary for the brain to clear out toxins, including B-amyloid protein, a precursor to Alzheimer’s disease.

When our sleep is shortened or we have sleep problems, “Immediate effects at the individual level relate to well-being, performance, daytime sleepiness and fatigue” (Ferrie et al., 2011, p. 1432). Because we are drowsy and fatigued, our reaction time slows down (Dinges, 2004), and we have more accidents. According to the US National Highway Traffic Safety Administration (as cited by Carpenter, 2013), driver fatigue leads to 100,000 accidents each year, with 1,550 deaths. Our decision making is compromised (Dinges, 2004), as is our impulse control, our emotional self-regulation, our cognitive executive functioning and concentration, and even such psychological factors as optimism, sociability, and resilience to stress (Carpenter, 2013). Even our pain sensitivity is increased. And studies have found a significant negative relationship between insufficient sleep and students’ GPA.

And insufficient sleep affects affects our physical health just as strongly. “Longer term evidence has accumulated of associations between sleep deprivation and sleep disorders and numerous health outcomes including premature mortality, cardiovascular disease, hypertension, inflammation, obesity, diabetes and impaired glucose tolerance, and psychiatric disorders, such as anxiety and depression” (Ferrie et al., 2011, p. 1432). NIH notes:  “Irregular [circadian] rhythms have been linked to various chronic health conditions, such as sleep disorders, obesity, diabetes, depression, bipolar disorder, and seasonal affective disorder.” (p. 2).

Worrying enough to disrupt your sleep?

There are some simple solutions: Bradford (2016) suggested that we should “avoid any exposure to blue light 30 to 60 minutes prior to bed. That means, no TV, tablets, computers or smart phones” (para 11). A dimly lit environment before bedtime will help you produce melatonin necessary for a good sleep that your daytime functioning and long term health need.

By the way, there is a rumour that Nap Pods will be coming to Cap for the Fall semester!


Carpenter, S. (2013). Awakening to sleep. [APA] Monitor on Psychology, 44(1), 40-45.

Ferrie, J. E., Kumari, M., Salo, P., Singh-Manoux, A. & Kivimaki, M. (2011). Sleep epidemiology – a rapidly growing field. International Journal of Epidemiology, 40(6), 1431-1437. doi: 10.1093/ije/dyr203

National Institute of General Medical Sciences (NIH), (2017). Circadian rhythms.

Winerman, L. (2004). Sleep deprivation threatens public health, says research award winner. APA Monitor on Psychology, 35(7), 61.