Seasonal affective disorder: Less light can mean darker moods

Primary care providers can help with SAD, holiday blues, COVID-19 stress, anxiety, depression and more

Does your mood seem to mirror the seasons - growing darker as the winter days get shorter and lifting as the brighter days of summer approach?

You could have a condition known as seasonal affective disorder (SAD). SAD is a type of depression that's related to seasonal changes in light. It can make you feel tired, crave carbohydrates, gain weight, avoid things you normally enjoy, or withdraw socially during the fall and winter months.

Sunlight helps regulate your internal biological clock. When there are changes in the amount of light you get, that clock gets out of balance, and levels of melatonin - a sleep-related hormone - can increase. This hormone may cause symptoms of depression.

Who is affected

Both children and adults can get SAD. However, it usually develops between the ages of 18 and 30. Four out of five people affected by SAD are women. Some evidence suggests that the further you live from the equator, the more likely you are to develop SAD.

According to the American Psychiatric Association, about 5 percent of adults in the United States experience SAD. For many, this is a recurring condition that visits from late fall to spring, with the most difficult months being January and February.

Although SAD is typically considered a fall and winter disorder, in a small number of cases, symptoms may be triggered by the longer, brighter days of summer. Some people also experience symptoms during periods of overcast weather, regardless of the season.

Shining a light

To be diagnosed with SAD, symptoms must reoccur at least twice at the same time each year, and then subside for the rest of the year.

If you have SAD, getting more sunlight may make you feel better. It may be helpful to take walks outdoors or be near a window during the day when at home or work.

If your symptoms are particularly bothersome, light therapy may be recommended. This involves using special lighting while indoors. Therapeutic lighting is much more intense than standard lighting and has been shown to decrease levels of melatonin in the brain.

Your healthcare provider can help you decide how long to spend in this lighting and the best time of day to do so. For many people with SAD, light therapy is very effective. However, if it does not work for you, your provider may have other suggestions, including taking medicine for depression. With proper treatment, SAD is manageable.

If you or someone you know is experiencing symptoms of SAD, anxiety, depression or other mental health conditions, please seek care. Primary care and walk-in clinic providers have the expertise and experience to help and, if needed, can also refer you to a specialist. So don’t hesitate to visit a walk-in clinic or schedule a clinic appointment if you are experiencing symptoms that are affecting your quality of life.

Aspirus has clinics throughout Wisconsin and the UP of Michigan. Aspirus also has walk-in clinics, where care is available without an appointment. To find an Aspirus clinic or walk-in clinic near you, call the Aspirus Customer Contact Center at 800-847-4707 or visit