KEY POINTS
- A large study found that sleep loss, regardless of type, negatively impacts overall emotional well-being.
- The study suggests women may be more susceptible to the emotional effects of sleep loss than men.
- Reasons for these differences are unclear, but potential factors include hormonal fluctuations.
In a world where sleep loss and the inevitable fatigue that accompanies it are often thought of as “givens,” a study published by the American Psychological Association suggests that we may want to reconsider that fatalistic mindset. An analysis of 154 sleep deprivation studies conducted over a 50-year period across 28 countries revealed that sleep loss doesn’t just make us feel tired. It adversely impacts a host of other critical functions, including our emotional responsiveness, mood, and anxiety levels, thereby making us more vulnerable to psychological distress and disorders (Palmer et al., 2023).
Described as the largest, most comprehensive analysis of experimental sleep and emotion research to date by the study’s lead author, Cara Palmer, she warns that the results provide strong evidence that all types of sleep interference, including extended periods of wakefulness (sleep deprivation), loss of just a few hours of sleep (sleep reduction), and intermittent nighttime awakenings (sleep fragmentation), have a detrimental impact on our overall physical and mental well-being. And decades of sleep research seem to back her up.
Studies found that sleep loss is a universal phenomenon (Basch et al., 2014; Liu et al., 2016; Public Health Agency of Canada, 2019; Walch et al., 2016). Palmer’s and colleague’s findings have clear physical, mental, and public safety implications for a large segment of the worldwide population, especially for teenagers and those working in professions particularly vulnerable to sleep loss, such as emergency personnel, night shift workers, and truck drivers.
However, as a Psychology Today blogger who writes primarily about women and stress, I was particularly interested in the authors’ a priori hypothesis that sleep loss would have more of an effect on emotional outcomes for females and their ultimate discovery of “stronger effect sizes for samples that included a higher percentage of women,” particularly the finding of significantly higher mood disturbances in females that participated in sleep fragmented studies. (Although they noted that “these findings should be interpreted with caution” since other emotional outcome effects, such as anxiety, seemed to have a great impact on males.)
To get a better sense of what implications their research may have for women in the real world, I asked Palmer for clarification on what their analysis actually revealed about sleep loss and its effect on women in particular (C. Palmer, personal communication, February 21, 2024). She explained that, for both men and women, sleep loss significantly reduced positive emotions, increased anxiety, and blunted the intensity of their emotional experiences. However, she noted,
“Given that prior work suggests that women are more likely to experience sleep disturbances, these findings are especially important for women who struggle with insufficient sleep due to insomnia, schedule constraints, health conditions, or other factors.”
When asked if she had any data (or an opinion based on data) that might explain why females, at least in some studies, seem more vulnerable to the emotional effects of sleep loss, Palmer pointed out that previous research suggests that females may be more sensitive to the neurobehavioral effects of sleep loss. For example, she said that in teen studies, researchers have found that poor sleep affects “next-day emotional experiences” more so in females than males.
She also noted data from adult studies that suggest that the effects of sleep loss may accumulate more quickly, and recovery sleep may not be as restorative for females in comparison to males, which she added may explain the sex differences in her analyses. However, she was careful to point out,
“Our findings suggest that there is a lot we still don’t know about why this is the case—future work will need to examine how women might be more or less vulnerable to the emotional effects of sleep loss during times of hormonal fluctuations (puberty, menopause, different stages of the menstrual cycle) or during life transitions, such as pregnancy/postpartum periods.”
While the jury is still out on whether, how, or why women may be more affected by sleep loss than men, considerable data, supported by this newest analysis, show that even a small amount of sleep loss can negatively impact women’s physical and emotional well-being. This makes prioritizing and protecting women’s sleep just as important as a healthy diet and exercise in maintaining (and, in some cases, improving) their physical and mental health and well-being.
So, what are some ways you can help make sleep an important part of your daily routine? In the same way that there are strategies you can use to be more productive during your waking hours, there are strategies you can employ to get the most out of the time you devote to sleep.
1. Make your bedroom a sleep-only zone. Avoid work, phone calls, television viewing, and computer use in your bedroom.
2. Make your bedroom a sleep-friendly zone. Darkness enhances sleep; light interferes with it, so darken your room as much as possible. Turn off everything that makes noise, especially your phone. If noise can’t be avoided, use earplugs or turn on white noise.
3. Make your mind a sleep-friendly zone. A busy mind is a sleep inhibitor. If you have trouble shutting down your brain, use simple relaxation techniques to calm your mind. Breathe slowly and deeply as you try to fall asleep. Concentrate on relaxing one muscle at a time. Mentally take yourself to a quiet, restful, relaxing place in your mind, or repeat a short, peaceful mantra until you fall asleep.
4. Stick to a routine. Pick a time to wake up every morning and a time to go to bed every night, and stick to this routine as closely as possible. Waking up and going to sleep at different times on different days throws off your natural sleep rhythms.
5. Avoid sleep interrupters. Certain foods, drinks, and activities are known to interfere with sleep and should, therefore, be avoided before bedtime. For example, although alcohol may help you fall asleep faster, it interferes with sleep later in the night, so avoid it before bedtime. Because caffeine stays in your system a long time after its intake, stop consuming caffeinated products by early afternoon so that it can be out of your system by bedtime.
If you know your system is bothered by certain kinds of food (e.g., if spicy or fatty foods tend to give you indigestion), just before bedtime would not be the best time to enjoy these kinds of meals. Finally, although physical activity can help you get a better night’s sleep, it often has the opposite effect if you exercise right before bedtime. Because exercise stimulates your body, it should be avoided several hours before bedtime.
Although incorporating all five of these strategies would be a definite home run for improving sleep quality and quantity, even including one or two will likely improve sleep, reduce fatigue, and boost mood.
References
Basch, C. E., Basch, C. H., Ruggles, K. V., & Rajan, S. (2014). Prevalence of sleep duration on an average school night among 4 nationally representative successive samples of American high school students, 2007–2013. Preventing Chronic Disease, 11, Article 140383. https:// doi.org/10.5888/pcd11.140383
Liu, Y., Wheaton, A. G., Chapman, D. P., Cunningham, T. J., Lu, H., & Croft, J. B. (2016). Prevalence of healthy sleep duration among adults— United States, 2014. MMWR. Morbidity and Mortality Weekly Report, 65(6), 137–141. https://doi.org/10.15585/mmwr.mm6506a1
Palmer, C. A., Bower, J. L., Cho, K. W., Clementi, M. A., Lau, S., Oosterhoff, B., & Alfano, C. A. (2023). Sleep loss and emotion: A systematic review and meta-analysis of over 50 years of experimental research. Psychological Bulletin. https://doi.org/10.1037/bul0000410
Public Health Agency of Canada. (2019). Are Canadian adults getting enough sleep? Infographic – Canada.ca
Walch, O. J., Cochran, A., & Forger, D. B. (2016). A global quantification of “normal” sleep schedules using smartphone data. Science Advances, 2(5), Article e1501705. https://doi.org/10.1126/sciadv.1501705.