What changes as the seasons change

As the days grow shorter and the light begins to fade earlier each afternoon, many people notice a shift in how they feel. Energy dips, sleep changes, motivation wanes, and the enthusiasm of summer can give way to a heavier, more withdrawn mood. At Breakthrough Mental Health LLC, we see this pattern every year — and the good news is that understanding it, and preparing for it, can make a real difference.

Why the Seasons Affect How We Feel

The change of seasons is more than a shift in weather. As daylight hours shrink in the fall and winter, our internal body clock — the circadian rhythm — can fall out of sync. These changes in light exposure influence sleep, hormones like melatonin, and brain chemicals such as serotonin that help regulate mood (Dollish et al., Neuron, 2024). For many people, this translates into real, noticeable changes in emotional well-being during the darker months.

Population research backs this up: average mood and mental well-being tend to be lower in winter than in summer, with low energy and sleep disturbance among the most common complaints (Guan et al., PLoS One, 2026).

Seasonal Affective Disorder: When Seasonal Changes Go Deeper

For some people, these seasonal shifts become a diagnosable form of depression called Seasonal Affective Disorder (SAD) — technically recognized as major depressive disorder (or bipolar disorder) with a seasonal pattern. About 5% of U.S. adults experience SAD, and symptoms typically begin in the fall or winter and lift in the spring or summer (Dollish et al., Neuron, 2024; Galima et al., American Family Physician, 2020).

Unlike many forms of depression, SAD often comes with "atypical" symptoms, including:

• Oversleeping and difficulty waking

• Increased appetite, especially cravings for carbohydrates

• Weight gain

• Profound fatigue and low energy

• Loss of interest in activities and social withdrawal

While winter is the most common time for symptoms, roughly 10% of people with SAD experience a summer pattern instead, which tends to involve insomnia and reduced appetite (Dollish et al., Neuron, 2024).

Who Is Most at Risk?

Certain factors make seasonal mood changes more likely (Galima et al., American Family Physician, 2020):

• A personal or family history of depression or bipolar disorder

• Being female

• Living at a more northern latitude, where winter days are shortest

• Being a young adult (roughly ages 18 to 30)

If you have a history of depression or bipolar disorder, it is especially worth paying attention to how the seasons affect you, since seasonal patterns can be linked to more frequent and more severe episodes (Zhang & Volkow, Translational Psychiatry, 2023).

How to Prepare Before the Days Get Shorter

The most powerful thing you can do is prepare early — ideally before symptoms take hold. Here are evidence-based steps to consider:

1. Get ahead of the light. Decreased exposure to light is thought to be a key driver of winter mood changes. Make a plan now to maximize natural daylight: open blinds, sit near windows, and get outside during daylight hours whenever possible (Galima et al., American Family Physician, 2020).

2. Consider light therapy. Light therapy is a well-established first-line treatment for SAD. It uses a "light box" delivering 2,500 to 10,000 lux, typically for 30 to 60 minutes each morning shortly after waking. It is low-risk and comparable in effect to antidepressant medication for many people. If you have an eye condition or take medications that make your eyes sensitive to light, check with your doctor first (Galima et al., American Family Physician, 2020; Chen et al., Journal of Affective Disorders, 2024).

3. Keep moving. Regular exercise and staying physically active are recommended lifestyle strategies that support mood through the darker months (Galima et al., American Family Physician, 2020).

4. Protect your routines and connections. Shorter days can quietly erode daily structure, physical activity, and face-to-face social contact — all of which matter for mental health. Building in regular routines and social plans ahead of time helps guard against the winter slide (Guan et al., PLoS One, 2026).

5. Talk to a professional about therapy. Cognitive behavioral therapy specifically adapted for SAD helps people manage the thoughts and behaviors that can deepen seasonal low mood, and it is an effective, well-supported treatment (Galima et al., American Family Physician, 2020).

6. Ask about preventive treatment if you've been here before.If you've had seasonal depression in past years, preventive strategies started before symptoms return can help. The medication bupropion, started in the fall before symptoms typically begin, has the strongest evidence for preventing recurrence and is the only medication specifically approved for this purpose. Continuing light therapy or other antidepressants may also help (Galima et al., American Family Physician, 2020).

When to Reach Out for Help

Seasonal changes in mood are common, but they are not something you simply have to endure. Reach out to a mental health professional if you notice:

• Low mood, hopelessness, or loss of interest that lasts more than two weeks

• Significant changes in sleep, appetite, or energy that interfere with daily life

• Difficulty functioning at work, school, or home

• Any thoughts of self-harm or that life isn't worth living — these warrant immediate help

If you are in crisis, call or text 988 (the Suicide and Crisis Lifeline) at any time.

You Don't Have to Face the Season Alone

The shift in seasons doesn't have to mean a shift in your well-being. With the right preparation and support, the darker months can be far more manageable. At Breakthrough Mental Health LLC, we're here to help you build a plan that fits your life — before the season changes, not after. Reach out today to learn how we can support your mental health all year round.

This article is for educational purposes and is not a substitute for individualized medical advice. Please consult a qualified health professional about your specific situation.