Research shows that somewhere around five percent of adults in America struggle with SAD each year, with symptoms lasting around 40 percent of the year.2 Some people experience milder symptoms, while others find that SAD has a major impact on their ability to function in day-to-day life.
The good news is that seasonal affective disorder also responds well to treatment. Learning more about your symptoms and exploring the different treatment options can give you the hope needed to start the recovery process.
For some people, outpatient therapy and light therapy provide sufficient relief for their depression. Others, however, might benefit from more intensive support through residential treatment programs that address the full scope of their symptoms.
This page will help you better understand the facts about seasonal affective disorder and your treatment options:
The primary symptoms of SAD can include:1
Low mood and sadness: Feeling down or empty almost every day.
The severity of SAD symptoms can range from mild to debilitating. Some people manage to maintain their daily responsibilities despite discomfort, while others find that SAD prevents them from working, caring for themselves, or maintaining relationships.
The biological reasons behind SAD can also be unique from other depressive disorders: Reduced sunlight exposure disrupts your body’s internal clock, known as the circadian rhythm, which regulates sleep-wake cycles, hormone production, and mood.4 When it gets dark earlier (and for longer), your brain produces more melatonin (a hormone that promotes sleepiness) which can leave you feeling sluggish and fatigued throughout the day.
Additionally, decreased sunlight affects serotonin levels in the brain.2 Serotonin helps you regulate mood, appetite, and sleep, and lower levels have been linked to depressive symptoms. People struggling with SAD can experience slower serotonin activity in the brain during the late fall and winter months, which might help to explain why their symptoms tend to improve as daylight hours extend.
Geography also factors into SAD risk: People living farther from the equator face higher rates of the disorder due to more dramatic seasonal light changes.5 For example, someone in Alaska or northern Canada experiences different daylight patterns than someone in Florida or California, making SAD more prevalent in northern areas.
Once you recognize your own unique patterns with seasonal-based depression, you can anticipate when symptoms might return and take the steps necessary to better manage them.
Another unique feature of SAD is the possibility of summer-pattern seasonal affective disorder, though this occurs far less frequently.6 Summer SAD usually involves different symptoms than winter-based SAD, including:
Insomnia
The exact causes of summer-pattern SAD is less understood, though heat, humidity, and longer daylight hours could all play a role.
AMFM is here to help you or your loved one take the next steps towards an improved mental well-being.
Vitamin D deficiency appears to play a big role, as reduced sunlight during winter months limits your body’s ability to produce this essential nutrient.7 Vitamin D also influences serotonin production and activity in the brain, and lower levels have been associated with an increased risk for depression.
Some studies suggest that people with SAD may have difficulty producing or absorbing enough vitamin D, even when taking a supplement.2
Genetic factors likely also influence your chances of developing SAD. Research suggests that seasonal affective disorder tends to run in families, with those having a parent or sibling with SAD facing a much higher risk of having or developing it themselves.8 People with a history of major depressive episodes or bipolar disorder show increased vulnerability to seasonal patterns of mood disturbance as well.
Ultimately, seasonal depression is likely a result of several environmental and genetic interactions, known as epigenetics or bidirectionality.9 Your brain chemistry and how well you are able to regulate neurotransmitters will impact whether shortened daylight hours trigger depressive symptoms or leave you relatively unaffected.
While some people with seasonal affective disorder respond well to things like light therapy and vitamin D supplementation on their own, many people find their symptoms require more support.
Inpatient treatment offers an intensive, supportive level of care for anyone whose depression has severely impacted their ability to function. Residential treatment programs for seasonal depression provide an environment where you can focus entirely on stabilization and recovery without the distractions and stressors of daily life, lasting anywhere from several weeks to a few months and providing 24/7 support from professionals.
Inpatient care for seasonal depression combines multiple evidence-based approaches to tackle the biological and psychological aspects of the disorder. Your treatment team will do a full assessment to understand the extent of your symptoms, any potential co-occurring mental health conditions, and the environmental factors contributing to your struggles.
The best inpatient programs also offer specialized treatments for seasonal affective disorder, such as cognitive-behavioral therapy adapted for SAD (CBT-SAD). CBT for SAD helps you identify and challenge unhelpful thought patterns and develop new strategies for handling seasonal-based challenges. Group therapy sessions for SAD can connect you with others facing similar struggles, providing peer-based support and helping to reduce the isolation that often makes feeling depressed so hard.
Many SAD therapy inpatient programs also offer activities like yoga and meditation, art therapy, and animal-assisted therapy to help you reconnect with activities and experiences that bring meaning to your life.
Before completing treatment, your team will co-create a detailed plan with you to manage symptoms during future seasonal changes, which might include engaging with outpatient therapy and support, maintaining light therapy routines at home, and recognizing any early warning signs of future depressive episodes.
Psychiatrists will work closely with you to find the right antidepressant medication and dosage to address your symptoms if needed. Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for SAD, and inpatient care allows your treatment team to monitor medication effects closely and make any adjustments quickly if needed.
A Mission For Michael (AMFM) provides treatment for adults experiencing various conditions. Depression support is a phone call away – call 866-478-4383 to learn about our current treatment options.
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You don’t need to face another difficult season alone. A Mission for Michael has the clinical experience and compassionate understanding you or your loved one needs to break free from the cycles of season-based depression and other mental health struggles.
Each of our treatment plans are uniquely designed for your journey and needs, combining the best in evidence-based care with holistic approaches that speak to your experience. Our residential treatment, intensive outpatient care, and ongoing supportive services can get you the care you need, and our team is standing by to talk you through all your options.
If you’re ready to take the next steps forward, contact A Mission For Michael today.
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SAD often follows a predictable seasonal pattern, most commonly worsening in late fall or winter and easing as daylight returns. If you notice this cycle year after year—especially with low mood, fatigue, oversleeping, social withdrawal, or changes in appetite—it may be worth getting a professional assessment so you can get the right kind of support.
Many people experience persistent low mood, loss of interest in activities, low energy, oversleeping, difficulty concentrating, cravings for comfort foods or weight changes, guilt or negative self-talk, and pulling away from friends or family. Symptoms can range from mild to debilitating, and you deserve support at any level of severity.
Yes—while it’s less common, some people experience a summer-pattern form of SAD. It may look different than winter SAD and can include symptoms like insomnia, reduced appetite, weight loss, or agitation.
Inpatient care provides a structured environment where you can focus fully on stabilization and recovery, with a treatment team that completes a comprehensive assessment and uses multiple approaches—often including CBT-SAD, group support, and therapies that help you reconnect with meaningful activities. Before discharge, we work with you on a plan for future seasons, including recognizing early warning signs and building ongoing supports.
Length of stay depends on your symptoms and goals, but many programs are around 2–8 weeks, with progress reviewed throughout treatment. If you’ve tried outpatient counseling, light therapy, or medication and still feel stuck, inpatient care can help by offering more targeted, coordinated treatment and consistent 24/7 support.
[1] National Institute of Mental Health. (2023). Seasonal Affective Disorder. Www.nimh.nih.gov; National Institute of Mental Health. https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder
[2] Torres, F. (2020). Seasonal affective disorder (SAD). American Psychiatric Association. https://www.psychiatry.org/Patients-Families/Seasonal-Affective-Disorder
[3] Major Depressive Disorder with a Seasonal Pattern | NAMI. (2017, August). Www.nami.org. https://www.nami.org/about-mental-illness/mental-health-conditions/depression/major-depressive-disorder-with-a-seasonal-pattern/
[4] Epstein, L. (2020, May 13). Why your sleep and wake cycles affect your mood. Harvard Health Blog. https://www.health.harvard.edu/blog/why-your-sleep-and-wake-cycles-affect-your-mood-2020051319792
[5] Kim, K., Kim, J., Jung, S., Kim, H.-W., Kim, H.-S., Son, E., Ko, D. S., Yoon, S., Kim, B. S., Kim, W. K., Lim, C., Kim, K., Lee, D., & Kim, Y. H. (2025). Global prevalence of seasonal affective disorder by latitude: A systematic review and meta-analysis. Journal of Affective Disorders, 390, 119807. https://doi.org/10.1016/j.jad.2025.119807
[6] Yes, You Can Get SAD in Summer. (n.d.). Cleveland Clinic. https://health.clevelandclinic.org/summer-depression
[7] Jahan-Mihan, A., Stevens, P., Medero-Alfonso, S., Brace, G., Overby, L. K., Berg, K., & Labyak, C. (2024). The Role of Water-Soluble Vitamins and Vitamin D in Prevention and Treatment of Depression and Seasonal Affective Disorder in Adults. Nutrients, 16(12), 1902. https://doi.org/10.3390/nu16121902
[8] Munir, S., & Abbas, M. (2022). Seasonal Depressive Disorder. Nih.gov; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK568745/
[9] Peedicayil, J. (2018). The relevance of epigenetics to seasonal affective disorder. Journal of Affective Disorders, 239, 201–202. https://doi.org/10.1016/j.jad.2018.07.015
