Credit: iStock

If you feel sad, gloomy and hopeless more often in the winter months compared to the rest of the year, you’re not alone. Between 4 and 6 percent of adults in the U.S. have been diagnosed with seasonal affective disorder (SAD), also known as winter depression. Another 10 to 20 percent may not have an official diagnosis of SAD but experience milder symptoms of seasonal depression. People with SAD usually start feeling down in the late fall and into the winter months each year.

Seasonal mood variations are related mostly to daylight, not temperature. The farther you live from the equator, the more likely you are to have SAD. Tucson, Arizona, for example, gets an average of 8.5 hours of sunlight per day in the height of winter. Compare that to people living in Anchorage, Alaska, who see just under three hours of daily sunlight, which puts them at a much higher risk for SAD. Long stretches of overcast weather—think Seattle or Vancouver, Canada—can also make symptoms worse.

SAD is more common in women and young people, but the exact causes are unknown. Some experts think that a disruption to circadian rhythm, reduced levels of serotonin (a chemical related to mood) and changes in melatonin levels (a hormone that makes you feel sleepy) may contribute to the development of SAD.

Symptoms of SAD/winter depression may include:

• loss of interest in activities you used to enjoy,
• low energy,
• trouble sleeping or sleeping too much,
• cravings for carbohydrate-rich foods, and
• thoughts of suicide or death.

Medication, talk therapy (counseling) and light therapy—also called phototherapy—are common ways to treat SAD. A 2017 study published in the Journal of College Student Psychotherapy showed that college students had a significant improvement in overall depression scores after participating in light therapy. Buying a light therapy box may be an affordable treatment method. Some light therapy boxes mimic the progression of a sunrise, even when the sun is hours from rising.

Certain lifestyle behaviors may also help to improve symptoms of SAD, including:

• getting outside when it’s light out,
• opening up window blinds and curtains,
• sitting near a window during daylight hours and
• getting regular exercise.

It’s important to know that sadness is a healthy emotion and helps us connect and respond to our environment in a more positive manner. However, if sad moods seem to be more chronic than seasonal, contact MentalHealth.gov for help.

Amanda Jo LeBlanc, PhD, is a cardiovascular physiologist and an associate professor at the University of Louisville School of Medicine. She studies microvascular function in aging.