Seasonal affective disorder, or SAD, is a type of depression that happens during the fall and winter months when there is less natural sunlight. Shorter days can affect the body’s internal clock and brain chemicals that help regulate mood.
Common symptoms of SAD include:
- Feeling tired or low in energy
- Feeling sad or depressed
- Sleeping more than usual
- Craving carbohydrates or overeating
- Gaining weight
- Wanting to withdraw socially
One of the most effective ways to support people with SAD is bright light therapy. Sitting near a special light box for about 30 minutes each day can help improve mood and energy for many people. Light therapy works by helping reset the body’s natural rhythm and supporting healthy brain chemistry.
Seasonal changes can also affect serotonin, a brain chemical involved in mood. This helps explain why some people feel worse during darker months and better when daylight increases.
SAD is more common in women and usually begins in young or middle adulthood. Some people have mild seasonal mood changes, while others experience more significant symptoms.
Light exposure, regular sleep habits, physical activity, and other lifestyle approaches are often used together to help manage seasonal mood changes.
