As the temperature drops and days get shorter, an occasional case of the winter blues is unavoidable for most of us — prolonged periods of winter weather and little sunlight make many people feel a bit lethargic or gloomy. But according to Cleveland Clinic, about five percent of U.S. adults experience a form of depression tied to this seasonal shift: seasonal affective disorder (SAD). This major depressive disorder pattern tends to occur during winter — though about 10 percent of people with SAD experience its effects with the onset of summer weather.
SAD is a type of depression — so its symptoms often mirror those of other depressive disorders. The difference is that people with SAD experience some combination of these criteria for depression in a seasonal way:
• Losing interest in activities
• Feeling fatigued, drowsy, unfocused, anxious, or irritable
• Difficulty sleeping
• Changes to appetite and fluctuations in weight
• Changes in libido
• A desire to socially isolate
• Physical issues such as headaches
Researchers believe the root causes of SAD may come down to how seasonal changes affect a person’s biological clock and their sensitivity to daylight duration, says Carly Claney, PhD, a licensed clinical psychologist and the director of Relational Psych.
Here’s how it works:
Our bodies operate on a 24-hour cycle known as the circadian rhythm. This biological clock helps control our daily sleep schedule and regulate our moods — and it primarily works in response to light exposure.
A lot of external factors can upset this natural cycle, like insomnia, shift work, jet lag, and decreased sunlight. That’s why researchers believe that long winter nights can make it more difficult for some people to regulate their moods.
Changes to our circadian rhythm affect our body’s hormone regulation as well. Research published in The Journal of the European College of Neuropsychopharmacology found that low sun exposure can reduce a person’s level of serotonin — the hormone that helps control our mood, happiness, and feelings of well-being.
A lack of sunlight can also boost the body’s production of melatonin, the hormone that encourages sleep. That’s why people with SAD often feel sluggish and tired throughout the day during winter’s shorter days, according to the Mayo Clinic.
According to the Cleveland Clinic, SAD is most common in younger people and women.
You’re also more at risk for developing SAD if:
• You have an existing mental health condition, such as a major depressive disorder, an anxiety disorder, or an attention deficit hyperactivity disorder
• You have a family history of psychological conditions
• You live in a region further from the equator, and therefore with greater seasonal changes in daylight
Managing SAD is about bringing your body’s natural rhythms back into balance, says Janine Ilsley, LMSW, RYT-500, an integrative therapist at Cobb Psychotherapy in New York. Here are some tips:
“If you are displaying signs of SAD, schedules are vital, as you want to stick to your routine and not your mood,” says Rachel Cavallaro, PsyD, LP, MAP, a licensed psychologist with Thriveworks in Boston.
"Being exposed to as much natural light as possible is also helpful, so you want to be sure to open up the blinds and let the light shine in,” Cavallaro says.
It can also help to get outside during the day, which boosts your serotonin levels.
“There is also a large base of scientific research out there that supports the use of light box therapy to assist in regulating circadian rhythms,” Ilsley says.
According to the Mayo Clinic, light therapy is most effective with:
• a 10,000-lux intensity at a distance of 16 to 24 inches from your face
• daily sessions of about 20 to 30 minutes
• a morning-based schedule
Research shows that cognitive-behavioral therapy (CBT) can be effective in reducing the severity and annual recurrence of SAD.
CBT helps people identify and replace the negative thoughts driving their SAD — and it can effectively complement other therapies like light therapy or antidepressant use.
It’s normal to feel a bit gloomy when you’re stuck inside more often during the winter. But if the winter blues start affecting your relationships, work, or ability to enjoy daily life, exploring treatment options with a healthcare provider, professional counselor, or psychologist can help you learn to manage these seasonal shifts.
If you have questions about SAD, you can make a virtual appointment to talk to a healthcare provider via carbonhealth.com or through the Carbon Health app (virtual mental health appointments are currently available to California residents). If you or a loved one is experiencing thoughts of self-harm, seek emergency medical care or call the National Suicide Prevention Lifeline at any time, day or night, for free and confidential support, at 1-800-273-8255.