Roy Exum: The Winter Blues

Thursday, December 2, 2021 - by Roy Exum
Roy Exum
Roy Exum

Doctors call it Seasonal Affective Disorder (SAD) and scientists are convinced about 10 million Americans suffer from what is commonly known as ‘The Winter Blues.’ Now about the last thing I want to write about is SAD and I know some people will not warm to the subject. But those who know me best know that I’ve had a problem with depression for years. I dutifully take two pills a day and function extremely well.

I can’t tell I take the pills and doubt anyone else can either. But let me miss for a week or two and “the black dog” will begin to circle, as Sir Winston Churchill called his bouts with depression. I am very open about my depression in hopes I might inspire a “fellow struggler” to get help and feel as good as I do.

As far as I am concerned, mental health is just as common as physical health – no shame about it - and, in most cases, is easily managed by a professional physician.

‘The Winter Blues’ are very real and the worst cases can lead to dark places. There are more suicides between Thanksgiving and Christmas than at any other time of the year. Do you realize how many people can benefit – get this – from a brisk walk in winter’s sunshine? The article you are about to read proves it. And if you are in a spot where the problem may be tougher than Seasonal Affective Disorder, maybe you need to take two simple pills every morning like I do … under a doctor’s care, of course.

* * *


By Liz Schondelmayer, Michigan State University.

As the days continue to get shorter and colder, it’s likely that you or someone you know has started to experience seasonal mood changes.

Symptoms such as a loss of energy, a dip in mood, a lack of interest, or trouble focusing can often be attributed to the lack of daylight we take in. When these symptoms get too disruptive, they can be indicative of a mood disorder called seasonal affective disorder (SAD).

Over 10 million Americans have SAD, which is a type of depression that affects people during the fall and winter months when access to light is limited. But how does light play such a significant role in moderating mental and cognitive health?

Lily Yan, an associate professor in the Michigan State University (MSU) psychology department and director of the Light, Emotion and Cognition lab, explains how light exposure affects our mood, memory, and motivation.

Reporter: First of all, what is seasonal affective disorder, and what are some associated symptoms?

Lily Yan: SAD is a type of major depression that is characterized by a seasonal pattern of depressive symptoms for at least two years in a row. Though many of us may not meet the exact diagnostic criteria for major depression during the winter, we still may experience a lighter form of these symptoms, often referred to as the “winter blues.”

Most people who experience this type of depression don’t necessarily feel sad, but instead, deal with an energy crisis that leaves them feeling tired all of the time, withdrawn from social activities, unable to sleep well, and unable to concentrate or focus.

Reporter: When did you start studying this topic, and how do you conduct your research?

Yan: My previous research focused on understanding our circadian rhythm (which is our bodies’ natural 24-hour sleep-wake cycle), and how circadian rhythms are influenced by environmental lighting conditions. Since I started working at MSU in 2008, I began to explore how light affects emotions and cognition, as these functions are known to be impacted by the circadian system. In 2012, I received a grant from the National Institute of Mental Health to start the research program on light, emotion, and cognition.

The phenomena behind SAD has been known for decades, but I feel like there is still a gap in the literature around this topic: we don’t know enough about how light affects our mental health. This research can be challenging, as it is difficult to use human subjects to study neurobiological mechanisms and most laboratory animals are nocturnal, which respond to light oppositely from humans. However, […] we have a very unique resource: a diurnal rodent model (meaning that they are awake during the day, just like humans). Using this model, my research program aims to understand how light interacts with our brains at the molecular, cellular, and circuit level.

Reporter: How does light affect the mechanics of our brains underlying mood and cognition?

Yan: The dominant theory in this field is that light affects our circadian rhythm by training our brain’s internal clock and keeping it synchronized with our environment. However, when our circadian rhythm is interrupted by changes in the light cycle, that can cause cognitive and emotional issues such as irregular sleep patterns and moodiness.

In addition to regulating circadian rhythms, prior research has demonstrated that seasonal lighting condition can influence the amount of neurotransmitters (like serotonin and dopamine) present in the brain—meaning that in summer months, your brain is actually storing more of the chemicals that make you feel happy, alert, and motivated.

When we transition to a dark, cloudy season from a bright, sunny season, there are changes happening in the brain at an anatomical level. The results of one study, which included over 400 human subjects, demonstrate that the hippocampus—the part of our brains that controls many of our cognitive functions such as learning and remembering—is actually physically smaller during the winter and changes based on the seasons.

Reporter: How does research with rodents inform larger questions about human emotion and cognitive functions?

Yan: When working with diurnal rodents, we find that a lot of their behavioral and neurobiological responses to light conditions are consistent with those of humans. When conducting this research, we only change one factor at a time, which is the amount of light or light intensity the rodents receive during the day. We’ve found that when limiting their daytime light exposure, it results in many behavioral changes: for example, the rodents struggle to feel pleasure and/or remember things.

Rodents generally like sweet-tasting things, but after a few weeks in a winter-like dim light condition, they stop caring about eating things that are sweet and just go for whatever is most easily available. But in a regular condition with more light, they get excited about the sweet-tasting treats again and try to get them. Additionally, we see a lower sex drive in males housed in dim light conditions. The animals housed in dim light also have lower levels of serotonin and dopamine in their brain compared to those in bright light. These results help to establish diurnal rodents as a viable model to study the effects of light on the brain that are relevant to SAD in humans.

We’ve also conducted research to test the impact of daytime light exposure on the rodents’ spatial learning and memory. When navigating a maze, the rodents housed in a dim light condition struggle to remember the course, but the animals from a bright light condition are able to complete the maze. We also found that in dim lighting conditions, there are fewer dendritic spines (which allow neurons to receive information) connecting neurons together in the hippocampus. This may explain why it is harder to process and store information when we are exposed to less daylight.

Further research has shown that a neuropeptide (a type of neurotransmitter) called orexin plays a role in regulating light-dependent changes in learning and memory. In a recent study, we gave rodents housed in a winter-like condition this neuropeptide every day in a row for five days, and found that their ability to learn and retain new information improved significantly. On the flip side, when we gave rodents in a summer-like condition a treatment that blocks their ability to receive orexin, the rodents were impaired in their cognitive abilities. These results point to orexin as an important neurotransmitter in mediating the effects of light conditions.

Our future work will aim to further elucidate the neural mechanisms underlying the impact of bright sunny days or dark gloomy days on the brain, from the level of gene expression to neural circuitry. The diurnal rodent model offers an opportunity to answer those questions, which can be translated to understand SAD and winter blues in humans.

Reporter: Given this understanding of SAD and the winter blues, what are some ways to lessen SAD-like symptoms during the wintertime?

Yan: If you are looking to get a diagnosis or need help managing a case of SAD, my advice is to seek professional help from a mental health care provider first.

However, if you’re just looking to improve your energy or motivation level during the winter months, I definitely recommend spending more time outside. Even though the cold weather can make it difficult, outdoor lighting is still way brighter than indoor lighting, even on a cloudy or overcast day. You could also look into a light therapy box to make indoor lighting even brighter.

In the future, I hope a better understanding of the mechanisms underlying the effects of light on mood and cognition will lead to the development of new strategies for treating SAD, as well as other types of depressive disorders and cognitive impairments. Until then, light will remain as one of the most effective treatments for SAD and winter blues.

For my undergraduate classes, I always share the following quote from Albus Dumbledore: “Happiness can be found even in the darkest of times, as long as one remembers to turn on the light.”

- - -

(This article was originally published by Michigan State University. Republished via under Creative Commons License 4.0, and reprinted in the Epoch Times on Nov. 26, 2021.)

How Pelosi’s Visit Proves Everyone Has A Stake In The US-Taiwan Partnership

Honoring Claude Ramsey And Dalton Roberts Is Long Overdue

Is Chattanooga Running Out Of Ideas?

Speaker Nancy Pelosi’s decision to go to Taiwan wasn’t crazy or foolish. There’s a reason that 26 Republican senators reached across the aisle to show support for someone long-considered their ... (click for more)

I am so grateful that County Attorney Rheubin Taylor and others are honoring our former County Mayors Claude Ramsey and Dalton Roberts. It goes without saying that this is long overdue. I have ... (click for more)

It seems every time we need an anchor for a new area added to the RiverCity footprint, we move a stadium. Is Chattanooga running out of ideas? The baffling unanimity of the city council on the ... (click for more)


How Pelosi’s Visit Proves Everyone Has A Stake In The US-Taiwan Partnership

Speaker Nancy Pelosi’s decision to go to Taiwan wasn’t crazy or foolish. There’s a reason that 26 Republican senators reached across the aisle to show support for someone long-considered their political adversary. Pelosi’s visit highlights that it’s more than just principles on the line--it’s the entire global order. Pelosi stated there were three main pillars to this US-Taiwan ... (click for more)

Honoring Claude Ramsey And Dalton Roberts Is Long Overdue

I am so grateful that County Attorney Rheubin Taylor and others are honoring our former County Mayors Claude Ramsey and Dalton Roberts. It goes without saying that this is long overdue. I have seen the Bredesen-Ramsey interchange near Volkswagen Drive, but Claude certainly deserves additional recognition for his contributions to our county. As for Dalton, I have pushed for years ... (click for more)

Breaking News

Couple Shot In Hixson As They Lay In Bed Early Thursday Morning

Chattanooga Police said two people were shot early Thursday morning as they lay in bed at their residence in Hixson. At 1:30 a.m., Chattanooga Police responded to a shooting at 4900 Lavender Trail. Police were advised that two people suffering from non-life threatening injuries had driven themselves to a local hospital for treatment. They were a man 22 and a woman 26. ... (click for more)

Biden Administration Announces $25 Million for Wilcox Bridge, $14.6 Milllion To Dunlap For Highway 127 Intersection Improvement

U.S. Secretary of Transportation Pete Buttigieg on Thursday announced that the Biden-Harris Administration has awarded $63 million to support three projects in Tennessee from the Rebuilding American Infrastructure with Sustainability and Equity (RAISE) program to help move forward on projects that modernize roads, bridges, transit, rail, ports, and intermodal transportation and ... (click for more)


WindStone Chosen As Host Site For 2022 National Car Rental PGA Jr. League Regional

Twelve golf facilities across the nation, including WindStone in Ringgold, Ga., have been named host sites for the 2022 National Car Rental PGA Jr. League Regionals taking place in September. Nearly 200 teams of junior golfers ages 10-17 will enjoy two days of competition. Through PGA Jr. League, kids ages 17 and under learn and play golf on co-ed teams, wear numbered jerseys ... (click for more)

UTC Football Fall Practice Preview

Palpable excitement filled the air this past Tuesday evening at Finley Stadium. As players in various states of undress poured out from a pair of school buses and into the locker room, equipment managers and assistant coaches scurried to set up equipment. The hits of Drake, Future, and other rap stars began to play from the stadium’s loudspeakers as players, now uniformly outfitted ... (click for more)