October 9, 2026
Chasing the Light: Understanding Seasonal Depression
If you have noticed it getting harder to get out of bed lately, you are not imagining it. Here in central Iowa, we lose a few minutes of daylight every day this time of year. When daylight saving time ends on Sunday, November 1, sunset will jump to around 5 p.m. By the winter solstice, Des Moines gets barely nine hours of daylight, about six fewer than in June.
For many people, that shift brings a little sluggishness, craving for comfort food, and no desire to be outside. For others, it brings something heavier: a real, recurring depression that arrives with the fall and lifts with the spring. This pattern is called seasonal affective disorder (SAD), and it is very treatable.
Winter blues, or something more?
SAD is a form of depression that follows the seasons. In clinical terms, it is major depression with a seasonal pattern: episodes start at about the same time each year and fully resolve when the season changes, typically for at least two years in a row.
The "winter blues" are common and milder. You might feel a bit flat, sleep a little more, or miss the sunshine, but you still function well and enjoy the things you care about. SAD is different. It gets in the way of work, relationships, and daily life, and it tends to last for months rather than days.
Most people with SAD have a fall and winter pattern. Others may experience a summer pattern, often with poor sleep, low appetite, and restlessness.
What it can look like
Winter-pattern SAD often feels like your body is trying to hibernate. Common signs include:
• Low mood most of the day, nearly every day
• Losing interest in things you usually enjoy
• Sleeping much more than usual and still feeling tired
• Heavy, low-energy days, sometimes described as feeling like your limbs are made of lead
• Craving carbohydrates and sweets, often with weight gain
• Trouble concentrating or making decisions
• Pulling away from friends, family, and activities
• Feeling hopeless, worthless, or guilty
The key clue is timing. If these changes show up around the same time every fall and fade by spring, it is worth paying attention to the pattern.
Why less light affects mood
Over the years, researchers have tried to pinpoint the exact cause for this phenomenon. Ultimately it comes down to light, specifically daylight. Your brain uses morning light to set its internal clock. This internal clock is called the circadian rhythm. Your circadian rhythm guides sleep, energy, and hormones. When mornings stay dark, that clock can drift out of sync with your daily schedule.
Several other changes seem to play a part:
• Melatonin. Longer nights mean the body makes more of this sleep hormone, which can leave you groggy and slow.
• Serotonin. Less sunlight is linked to lower activity of serotonin, a brain chemical that helps regulate mood.
• Vitamin D. Our skin makes vitamin D from sunlight, and levels often dip in winter. Low vitamin D has been linked to depression, though it is not the whole explanation.
Your changing mood is not a sign of weakness or a lack of willpower. It truly is a biological response to a changing environment.
Who is more likely to experience it
Anyone can develop SAD, but some factors raise the odds:
• Where you live. SAD is more common the farther you live from the equator. That puts Iowans at higher risk than people in the southern states.
• Sex and age. Women are diagnosed far more often than men, and symptoms usually begin in young adulthood.
• Family history. Depression or SAD in close relatives increases risk.
• Existing mood conditions. People with depression or bipolar disorder may notice their symptoms worsen with the seasons.
Estimates suggest that roughly 5% of U.S. adults experience SAD, and many more have milder winter blues.
What helps
The good news: SAD responds well to treatment, and many people feel better within a few weeks. The best plan depends on your history and symptoms, so it is worth building it with a provider.
Light therapy. Sitting near a special light box each morning is one of the most effective treatments for winter-pattern SAD. Boxes rated at 10,000 lux are typically used for 20 to 30 minutes, soon after waking. Look for one that filters UV light. These can be found on Amazon or other stores. Talk with your provider first if you have bipolar disorder, eye conditions, or take medications that increase light sensitivity.
Talk therapy. Consistent appointments with your therapist can help people challenge winter-related negative thoughts and plan enjoyable activities through the dark months.
Medication. Antidepressants can be very effective and can be used for a season. For people with a clear yearly pattern, starting treatment before symptoms usually return can help prevent an episode altogether.
Daily habits that make a difference:
• Get outside in the morning, even on cloudy days
• Open blinds and sit near windows when you can
• Keep a consistent sleep and wake time, if possible on the weekends as well
• Move your body most days, ideally outdoors, but indoors works too
• Stay connected with people, even when you would rather stay in
• Ask your provider whether checking your vitamin D level makes sense
• Plan things to look forward to through the winter
When to reach out
If low mood has lasted two weeks or more, is affecting your work or relationships, or follows the same pattern every year, it is time to talk with someone. You do not have to wait until winter is in full swing. Fall is actually the best time to make a plan.
If you are having thoughts of suicide or harming yourself, call or text 988, the Suicide and Crisis Lifeline, any time of day. In an emergency, call 911.
At Resilient Health Services, we help people navigate seasonal and year-round mood changes with care that fits their lives. To schedule an appointment, call us at 515-461-8889.
The days will get longer again. Until then, you do not have to wait it out alone.
