Don’t Let Dark Mornings Get You Down
Humans, animals and plants are programmed to set time by the sun and to function best when living in sync with nature’s rhythms.
Original Authors: Dr. Karin Johnson and Lynne Lamberg | Blog edits by Dr. Alison Kole
We made it through the darkest month of the year, January. I write this as March 10, 2024 will mark yet another year we must adjust the clocks to Daylight Savings Time, once again disrupting our circadian rhythm for absolutely no healthy or logical reason.
So what happens come January? Sunsets are starting to get later as are the sunrises. For example, in January, the sun won’t rise until after 8 a.m. in Detroit, Indianapolis and some other U.S. cities. In Anchorage, Alaska, it won’t rise until after 10 a.m.
People who get up before sunrise miss seeing sunlight at the time of day in which bright light has its most powerful effect on body clocks. Humans, animals and plants are programmed to set time by the sun and to function best when living in sync with nature’s rhythms.
Exposure to sunlight when we awaken or soon after sets the pace for hundreds of internal systems that regulate every aspect of our lives. Our internal clocks govern our daily cycle of sleep and wakefulness, as well as our heart rate, blood pressure, body temperature and cell division. Our mental activities across the day also follow cycles that affect how alert or sleepy we feel, whether we’re cheerful or glum, and how well we focus, remember, make decisions and balance our checkbooks.
Shorter daylength as well as later sunrises may disrupt work and school performance and undermine overall well-being. About 5% of U.S. adults experience a seasonal depressive disorder that starts as days grow shorter in the fall, according to the American Psychiatric Association. Symptoms typically peak in January and February and may persist for four to five months.
Seasonal Affective Disorder, aptly known as SAD, occurs more frequently in women than in men. It affects more people living in northern states with shorter winter daylight hours, such as Vermont and New Hampshire, than those living in southern ones such as Arizona and Florida where daylight lasts longer.
People with SAD may oversleep or feel excessively fatigued, crave carbohydrates, eat more and gain weight. They also may have typical symptoms of depression such as feeling sad, down or irritable, losing interest in their usual activities, feeling hopeless or worthless, finding difficulty concentrating and having thoughts of not wanting to live. Some people experience more mood disturbances in summer months when daylight intensity peaks, although summer SAD occurs much less frequently than the winter version, according to the National Institute of Mental Health (NIMH).
Winter SAD differs from “holiday blues,” feelings of sadness or anxiety sparked by stress linked to events occurring at specific times of year, the NIMH cautions. Winter SAD’s onset and the symptoms associated with it predictably follow the late fall-early winter decline in daylight hours.
A century or more ago, wealthy people who experienced SAD in winter months often sought respite in sunny climates. Thanks to research that began in the 1980s, people with SAD can boost their daily light exposure today without leaving home. They can receive effective therapy with artificial bright light at the start of their day while they have breakfast or work. Sitting in front of a lightbox that provides light equivalent to morning sunlight, about 20 times brighter than ordinary indoor light, a dose of 10,000 lux for about 20 to 60 minutes, usually restores mood and other symptoms to their usual state. Some people also benefit from psychotherapy and anti-depressive medications.
Many people who don’t experience SAD still dislike darker, chillier winter mornings. Some blame the bi-annual switch from daylight saving time to standard time for their becoming more sluggish and gaining weight in winter months. Yet, that’s an unlikely cause. Many people spend less time exercising outdoors in the winter and more time indoors watching television, often while snacking on calorie-dense foods. Those habits along with other drawbacks posed by the shorter, colder days of winter are more likely culprits here than the clock change.
During the eight months that daylight saving time is in effect in the U.S., from mid-March to early November, sunrises and sunsets shift an hour later. For much of that time, sunrise occurs early enough to get adequate morning light exposure, and our body clocks stay closely aligned with sun time. Our schedules force many of us to wake up before our bodies are ready, however. When that alarm rings at 7 a.m., our bodies think it’s still 6 a.m. With late sunsets in the summer, many people find it harder to get to sleep at night than they do at other times of year. As a result, many of us get a little less sleep when daylight saving time is in effect. Having out of sync body rhythms increases our risk of physical and mental health problems.
It is not surprising that most Americans dislike the bi-annual clock change. A sudden shift in clock time is associated with more mood disturbances and mental health problems in the days to weeks following both spring and fall switches. While getting rid of the clock change would help eliminate these short-term effects, it is more important for our long-term mental health for us to be on standard time in the winter. Living in harmony with the natural world helps stabilize both bodily functions and moods.
The return to standard time holds numerous benefits for adolescents, who typically are sleep-deprived. Their schools generally start at or before 8 a.m., out of sync with their biological clocks that, from the start of puberty, push them to stay up later and sleep in later if allowed to do so.
During the six or seven months that schools are in session while daylight saving time is in effect, school start times force students to get up an hour earlier than they would on standard time.
Starting classes at 8:30 a.m. on daylight saving time, for instance, is the equivalent of starting classes at 7:30 a.m. standard time. In the spring and fall during daylight saving time, many students arise in the dark and travel to school in the dark.
Sunrise and sunset time vary by longitude and latitude. The further we live from the equator, the more uneven the difference in day length between winter and summer. More northerly areas have their latest sunrises and earliest sunsets in the winter. Later sunrises and sunsets also occur on the western edges of time zones.
Following standard time in the winter protects us from the later sunrises we would experience if we followed daylight saving time year-round. On permanent daylight saving time, most states would have sunrises after 8 a.m. for two to three months of the year. On permanent standard time, only northern locations on the western edge of some time zones would experience their latest sunrises that late.
Adding later sunrises to the short days of winter has exponentially worse effects on mood. When Russia tried permanent daylight saving time for three years, adolescents had the highest rates of SAD compared to years with either seasonal time changes or permanent standard time, when they had the lowest rates.
Adopting permanent standard time across the nation would foster better school performance and mental health in adolescents. It would benefit the rest of us, too, by enabling us to keep our body clocks more closely aligned with the sun all year long.
These tactics can help you sleep better and feel better in winter months:
1. Prioritize sleep. Give yourself enough time to get the sleep you need to feel alert.
2. Create a relaxing bedtime routine that limits your exposure to electronics.
3. Stick to the same wake-up time seven days a week.
4. Increase your morning light exposure. Have breakfast near a sunny window. Go outside as soon as you can.
5. Eat meals at regular times. Avoid eating two to three hours before bedtime if you have difficulty falling asleep at your preferred time.
6. Exercise regularly, outdoors if possible.
7. Make an effort to connect with family and friends and engage in other social activities such as volunteering.
8. If you’re feeling down, seek advice from your physician or other health care provider. You may benefit from using a 10,000 lux lightbox for 20 to 60 minutes early in the day.
Karin Johnson, M.D., is a professor of neurology at the University of Massachusetts Chan Medical School-Baystate and medical director of the Baystate Health Regional Sleep Program. She is co-chair of Coalition for Permanent Standard Time, vice-president of the nonprofit, nonpartisan Save Standard Time, as well as creator and host of its educational video series, “The Science of Clock Change.” You can listen to her speak about the dangers of daylight saving time on Season 1, Episode 4 of the Sleep Is My Waking Passion podcast.
Lynne Lamberg is a medical journalist and editor who writes frequently on sleep, biological clocks and mental health. She is the book editor of the National Association of Science Writers.
