There are so many beautiful and meaningful parts of autumn in Minnesota. But for some of us, this season brings more than cozy sweaters and football; it also signals a shift in mood, energy, or appetite that repeats year after year. If you’ve noticed yourself feeling “off” each fall and winter, you might be experiencing what is often called seasonal affective disorder (SAD). In this post we’ll cover what the research says, why it’s especially relevant here in Minnesota, and what to do if you’re affected.

What is SAD?

The term SAD refers to a pattern of mood changes that reliably begins in one season (most often fall or winter), continues through the darker months, and then eases in spring or summer. According to the Mayo Clinic, symptoms may include persistent low mood, loss of interest, low energy, oversleeping, increased appetite (especially carbohydrate cravings), weight gain and difficulty concentrating. 

It’s not just “feeling blue because it’s cold”. For many, the symptoms are enough to interfere with work, school, relationships or daily life.

Why Minnesota matters

Living in Minnesota means long, dark winter nights and relatively short daylight hours. Multiple studies suggest that SAD (or winter-pattern mood change) increases in prevalence at higher latitudes (further from the equator), where sunlight is reduced for longer stretches (Melrose, 2015). 

It is estimated that about 5% of the US population experiences seasonal depression, but at higher latitudes, in places like Minnesota, the estimate is closer to 10% (Larson, 2022). 

Living in Minnesota, we may have a higher-than-average chance of noticing seasonal shifts in mood or energy not because of snow and freezing temps, but simply because our northern latitude amplifies the light-/day-length change that is thought to drive this phenomenon.

What causes SAD?

The precise cause remains unknown, and likely there’s no single cause. But among the leading factors:

• Disruption of the body’s internal clock (circadian rhythm) caused by reduced daylight in winter.  

• Changes in serotonin neurotransmission: some studies show winter-onset patients with SAD have increased serotonin transport activity (which may reduce serotonin availability) compared to summer.  

• Changes in melatonin: darkness triggers more melatonin, which is linked to sleepiness and may contribute to mood change in winter.  

• Reduced vitamin D (due to less sunlight), less physical activity, social withdrawal, and behavioral changes in winter are also contributing factors (Melrose, 2015).

Because of these overlapping mechanisms, effective treatment often involves combining biological, behavioral and psychological strategies.

What treatment works for SAD?

• Bright light therapy (BLT): exposure each morning to a bright light (often ~10,000 lux) mimicking daylight is considered first-line treatment for Seasonal Affective Disorder. Studies show moderate to large benefit in winter-pattern mood disorders (Melrose, 2015).

• Cognitive-behavioral therapy adapted for seasonal patterns (CBT-SAD): helps people plan for the season, stay active, and address negative cognitions about winter. Some randomized trials suggest CBT-SAD is as effective as light therapy, and may have longer-term prevention benefits (Rohan et al., 2016).

• Routine behavioral strategies: maintaining a consistent sleep/wake schedule, morning outdoor light exposure (even on cloudy days), regular exercise, and structured pleasant activities. 

• Antidepressant medication: For more severe cases or when comorbid diagnoses with more significant mood disorders are present, medications may be considered in combination with light or CBT. (Note: treatment decisions should always be individualized and made in consultation with health professionals. Medication decisions should be made with prescribing physicians. It’s also worth noting that while these treatments are backed by research, they’re not guaranteed cures. Individual responses vary, so early monitoring and adjustment is key.)

Final words

Here in Minnesota, the shortened days, long nights, and cold months are part of our lived experience every year. And for some of us, they bring recurrent mood and energy shifts that deserve recognition and care. Humans are mammals after all. Our modern world can often leave us feeling disconnected from the natural world, but we are entirely impacted by it. Many mammals hibernate during the long winter months, and in some ways it is probably a natural response that humans may also feel a natural slowing down during this time of year.

Seasonal mood change isn’t a fault, it’s a signal. With awareness, structure, and support, you can move through the months ahead with more steadiness, connection, purpose and hope. If this resonates with you or someone you know, let’s talk. We’re here to help you plan for your winters and not just survive them, but live well all through the coldest days.

This blog post is written for educational purposes only and is not meant to be diagnostic or a replacement for mental health treatment or medical care.