Millions of people in the northern hemisphere are in the midst of the coldest, darkest time of the year. It’s all too easy for a seasonal malaise to leave people feeling tired and overwhelmed.
But it doesn’t have to be that way.
In navigating this difficult time for many, Washington State University researchers say prioritizing sleep health can make a big difference.
“Think about our need for sleep like you’re carrying a backpack,” said Lois James, an assistant dean of research with the College of Nursing who leads the WSU Sleep and Performance Research Center. “Every hour you’re awake, you add a brick to your backpack, and every hour you sleep, you take two of those bricks out. So, if you’re consistently awake for 16 hours and sleep for 8 hours you empty your backpack by the start of each day. If however you only get four hours of sleep, you’re effectively starting your day weighed down, which is the concept of sleep debt.”
In the short term, sleep deficiency impairs decision making, reduces reaction time and focus, and destabilizes mood. Chronic sleep deficiency elevates the risk for a host of diseases, ranging from gastrointestinal disorders, heart disease, and cancer, among other ailments.
The winter blues
Why exactly humans can experience downswings in mood associated with the seasons is still being explored. Fewer hours of sunlight can lead to a deficiency in Vitamin D, which is believed to promote serotonin activity critical to mood regulation.
While individuals can’t control how much sunlight is available on a given day, they can take steps like using a light therapy box or taking Vitamin D supplements during the winter months.
Think about our need for sleep like you’re carrying a backpack. Every hour you’re awake, you add a brick to your backpack, and every hour you sleep, you take two of those bricks out.
Lois James, assistant dean of research
WSU College of Nursing
The importance of light in regards to human health boils down to our nature, James explained.
“Our circadian rhythms are synched to the sun, meaning that we’re designed to be awake during the day and asleep at night, so when that’s disrupted by long periods of darkness, our natural rhythms are affected,” James said.
Trendy sleep aids
Humans naturally produce melatonin to regulate circadian cycles, with its production believed to be affected by daylight. While supplemental melatonin is popular, its effectiveness as a general sleep aid requires further study, James said. It’s also not fast-acting, taking upwards of two hours for an effect to be felt and its chronic use can affect the body’s natural production of melatonin.
James does note, however, that melatonin can be effective at jumpstarting circadian rhythms to a new setting, such as for individuals transitioning from day to night shifts.
Cannabis is another increasingly popular purported sleep aid, with a 2023 WSU study finding that upwards of 80% of cannabis users surveyed reported no longer using over-the-counter or prescribed sleep aids, including melatonin and benzodiazepines.
The trouble is, cannabis and its effects on sleep represent a black box for researchers, said Devon Hansen, an assistant professor in the Department of Translational Medicine and Physiology.
“The difficulty is that, while cannabis research is of immense interest to lawmakers, researchers, and the general public, its status as a federally classified schedule 1 drug means it takes a tremendous amount of time and effort to get approved to do studies,” Hansen said. “I will say, however, that these are very easy studies to recruit for.”
It took Hansen and her WSU colleagues two years to go through necessary approvals to do a study on the effects of cannabis on sleep deprived individuals. And while the team hasn’t yet been able to find statistically significant evidence of effects, they are preparing for studies with larger sample sizes to get a better idea of what’s happening.
Sleep tips
Trendy treatments and products aside, there are several core pillars to consider when evaluating sleep health.
Perhaps most important is the recommendation that adults get 7–9 hours of sleep daily. It’s during that time that our DNA undergoes vital repair and our brains process and store memories. And there’s plenty of work yet to be done to come to better grips with our need to sleep.
“That’s what makes sleep research so exciting,” Hansen said. “We know about some of the benefits, but there is so much more out there to learn.”
Researchers have found that our sleep cycles change as we age, with more time spent in phases of shallower sleep phases. This can lead to older adults waking up in the middle of the night, as they are more easily roused by light and sound.
These observations make it imperative to keep in mind three keys to ideal sleeping conditions: temperature, light, and sound. A good environment for sleep is generally five degrees colder than what you would like during the day, as well as being as dark and quiet as possible, James advises.
A good environment for sleep is generally five degrees colder than what you would like during the day, as well as being as dark and quiet as possible.
For those sensitive to caffeine, consumption should cease by midday. Avoiding things like nicotine and alcohol close to bedtime is advised. In the case of alcohol, while it is a depressant that can be effective at getting someone to fall asleep, it is bad at keeping someone asleep for long periods of time.
Technology is also a big topic in the realm of sleep. James and Hansen recommend people preparing for bed discontinue use of their devices at least 30 minutes beforehand and set their phones to automatically go into dark mode to reduce light. Having a consistent bedtime and waketime and a calming pre-bed routine is also helpful in ensuring a restful night of sleep.
