Beating the Winter Blues

11.30.25

As winter sets in and temperatures fall, it’s important to remember that it’s getting darker, too. This time of year, the sun sets much earlier, and seasonal depression creeps up on many of us. Seasonal depression typically begins in late fall and results in low energy, a lack of motivation, and feelings of hopelessness. For a while, I thought that seasonal depression was just a casual term people used to describe the feelings they experienced during the winter months, but I came to learn that seasonal depression is a medical condition also known as Seasonal Affective Disorder (SAD).

Cold, snowy day at the University of Michigan

The main reason SAD occurs is due to a lack of sunlight, which impacts the brain’s endorphins, such as serotonin and melatonin. In my previous posts, I have focused on ways humans can benefit their cognitive health by being outdoors, but that becomes difficult in the winter. So, for today’s post, I am going to focus on the scientific understanding of how seasonal depression affects us and how we can overcome it.

The amount of sunlight we get during the shortest winter days is about half of what we receive during the longest summer days. For example, Detroit gets about 9.5 hours of sunlight in January and about 14 hours in August. According to Howard E. LeWine, Chief Medical Editor at Harvard Health Publishing, sunlight exposure stimulates the hypothalamus, the part of the brain that controls the endocrine system and homeostasis functions such as hunger, body temperature, and circadian rhythm. When there is a decrease in sunlight, the circadian rhythm becomes disrupted, creating a chemical imbalance between serotonin and melatonin that causes people to feel low and lethargic.

LeWine further explains that SAD affects social interaction, appetite, energy, and daily functioning. This includes “problems with concentration and working memory — like having trouble recalling just-learned information or finding the right words when speaking.”

So, how can we combat this? The National Institute of Mental Health states that the best ways to combat SAD include light therapy, vitamin D, psychotherapy (counseling), and antidepressant medication. While each of these methods is beneficial, I want to explore ways people can get outside and interact with their environment during the winter to increase serotonin levels—similar to how gardening or lying in the sun on a warm summer day does.

Gloomy, empty street

Even though there are fewer hours of sunlight in winter, simply going on a quick walk outside during the daytime can trigger the body’s initial process of producing vitamin D. Researchers at Cornell University’s College of Veterinary Medicine state that just 10 minutes outside per day—whether you are active or not—can improve mood, focus, and physiological markers such as blood pressure and heart rate. Furthermore, when you take a walk in the winter, the cold weather activates your sympathetic nervous system, increasing alertness.

In addition to increased alertness, an article written by Dr. Erica Oberg, Beyond the Plunge: 3 Surprising Ways Cold Shock Supercharges Your Mind, explains that exposure to cold stimulates several brain chemicals responsible for mood and motivation. Studies show that cold exposure can increase dopamine levels by up to 250% and norepinephrine levels by up to 530%, sharpening mental clarity and enhancing concentration. Oberg explains that cold exposure allows for a significant boost in energy and sustained neurotransmitter activity without the crash associated with stimulants such as cocaine or Adderall.

The article further explains that cold exposure builds stress resilience by training the body to manage its stress response more effectively. Similar to taking an ice bath, cold shock activates the sympathetic nervous system, which controls the “fight-or-flight” response. However, when you take deep breaths and gradually adjust to the exposure, you strengthen your parasympathetic nervous system, which counteracts the sympathetic system by slowing heart rate and breathing—also known as the “rest-and-digest” response.

Your body does not need an ice bath to stimulate this response. Simply spending time in the wintry outdoors offers many of the same benefits. So, even though it can be difficult to find the motivation to leave your house and take a walk when the days grow darker, you can still enhance your mood and cognitive health with each minute you spend outside exposed to the cold winter weather.