--- title: Why shorter days can affect your mood—and what to do about it description: Seasonal affective disorder is a type of depression associated with the changing of the seasons. image: https://blog.massgeneralbrighamhealthplan.org/hubfs/iStock-2184476627.jpg --- [![MGB_Health_Plan_horiz_rgb-1](https://blog.massgeneralbrighamhealthplan.org/hubfs/Mass%20General%20Brigham%20Health%20Plan/Logos/MGB_Health_Plan_horiz_rgb-1.svg)](https://www.massgeneralbrighamhealthplan.org/) ![](https://blog.massgeneralbrighamhealthplan.org/hubfs/iStock-2184476627.jpg) # Why shorter days can affect your mood—and what to do about it Published by [Michael Buttimer](https://blog.massgeneralbrighamhealthplan.org/author/michael-buttimer) on December 03, 2025 As the temperature dips and days become shorter, many people may find themselves feeling down or having the “winter blues.” **Seasonal affective disorder (SAD)** is a type of depression associated with the changing of the seasons. It can occur any time of year, including the spring and summer, but SAD is most often associated with the fall and winter months. Not to be confused with the stressors associated with [holidays or family gatherings](https://blog.massgeneralbrighamhealthplan.org/navigating-family-gatherings-during-the-holidays), SAD occurs more often in individuals living in areas where daylight is scarce in the winter, like Alaska and New England. ### Signs and symptoms According to the [National Institute of Mental Health](https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder)[(NIMH)](https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder), millions of Americans experience SAD annually, but many don’t realize it. **Signs and symptoms of SAD may include**: - Persistent sad, anxious, or “empty” mood - Feelings of hopelessness or pessimism - Feelings of irritability, frustration, or restlessness - Feelings of guilt, worthlessness, or helplessness - Loss of interest or pleasure in hobbies and activities - Decreased energy, fatigue, or feeling slowed down - Difficulty concentrating, remembering, or making decisions - Changes in sleep or appetite or unplanned weight changes - Physical aches or pains, headaches, cramps, or digestive problems with no cause - Thoughts of death, suicide, or suicide attempts *If you or someone you know is having suicidal thoughts, call or text **988** to reach the Suicide & Crisis Lifeline.* *In life-threatening situations, call **911**.* ### Causes, treatment, and care       Although the exact cause of SAD is still being [studied](https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder), researchers are looking at how daylight exposure, vitamin D levels, and melatonin and serotonin production play a role in symptoms. According to the [Mayo Clinic](https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/diagnosis-treatment/drc-20364722), the following treatments and care can be used to help relieve the symptoms of SAD: - **Light therapy (phototherapy)**:Using a special light box to mimic daylight exposure, light therapy can help ease symptoms of SAD. Some individuals find that light therapy works best when combined with another type of care such as psychotherapy or medication. - **Psychotherapy (talk therapy)**:A type of therapy that involves talking with a therapist about thoughts, feelings, and behaviors. It can help alleviate symptoms and create coping strategies. - **Medications**: Doctors may prescribeantidepressants to help with symptoms. - **Self-care**:In coordination with the above care options, getting plenty of sunshine, going outside during the day, exercising, and creating a [sleep routine](https://blog.massgeneralbrighamhealthplan.org/try-these-sleep-tips-for-better-health-1) can help ease symptoms of SAD. Mental health is a key part of overall well-being, and we're here to help. Check out these [free and low-cost resources](https://blog.massgeneralbrighamhealthplan.org/accessing-resources-to-support-your-mental-health-and-wellness) for supporting your mental health. If you’re a **Mass General Brigham Health Plan member**, take a look at some of the [mental health resources](https://massgeneralbrighamhealthplan.org/members/Benefits/behavioral-health) available to you. Talk to your doctor if you’re experiencing symptoms of seasonal affective disorder. If you or someone you know is having suicidal thoughts, call or text **988** to reach the Suicide & Crisis Lifeline. In life-threatening situations, call **911**. [![Copy Option 3-4](https://blog.massgeneralbrighamhealthplan.org/hs-fs/hubfs/Copy%20Option%203-4.png?width=3000&height=1250&name=Copy%20Option%203-4.png)](https://massgeneralbrighamhealthplan.org/lp/financialhealth) [Back to Blog](https://blog.massgeneralbrighamhealthplan.org) ## Related articles ## [Navigating family gatherings during the holidays](https://blog.massgeneralbrighamhealthplan.org/navigating-family-gatherings-during-the-holidays) The holiday season is often a time of joy and togetherness. However, stressors can lead to holiday... 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