Understanding seasonal changes and mental health
October 6, 2025
As fall approaches and the weather cools, many people notice changes in their mood, energy and sleep patterns. Shorter days and longer nights can disrupt the body’s natural circadian rhythm, which plays an important role in our emotional well-being.
While some refer to this as the “winter blues,” it’s important to understand that true Seasonal Affective Disorder (SAD) is not a separate diagnosis but rather may be an indicator of another mood disorder such as Major Depressive Disorder or Bipolar Disorder, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
"Feeling down for a short period of time can be normal," says Susan S. Hill, MS, LMFT. "When seasons change, your mood can too but if symptoms persist or become serious, it's important to seek out help right away. You don't have to face it alone."
What is seasonal affective disorder (SAD)?
According to the DSM-5, SAD describes a pattern of depressive or manic episodes that occur during certain seasons for at least two consecutive years. While it most commonly occurs during fall and winter months, some people experience the effects of SAD in spring or summer.
Recognizing the symptoms
If you notice ongoing mood changes that interfere with daily life, especially those lasting for more than two weeks, it may be time to talk to your doctor or a mental health professional.
Symptoms can include:
- Regularly feeling sad or down
- Loss of interest in hobbies or activities
- Low energy or fatigue
- Oversleeping or trouble sleeping
- Craving carbohydrates, overeating, or drastic weight changes
- Difficulty concentrating
- Feelings of hopelessness, worthlessness, or guilt
Symptoms can vary throughout the seasons; some patterns to notice during fall and winter can include:
- Oversleeping
- Increased appetite, especially carb cravings
- Weight gain
- Tiredness or low energy
During the spring and summer, symptoms can include:
- Trouble sleeping (insomnia)
- Decreased appetite
- Weight loss
- Anxiety, restlessness, or irritability
What can cause seasonal mood changes?
The exact cause of SAD isn’t fully understood, but there are a few things that might contribute to it:
- Circadian rhythm (biological clock). Reduced sunlight can disrupt the body's internal clock, affecting both your mood and sleep.
- Serotonin levels. Sunlight helps regulate serotonin, a chemical that influences mood. Less exposure to sunlight can lower the body's levels of serotonin.
- Melatonin levels. Seasonal changes can also disrupt melatonin, a hormone that influences sleep and mood
Managing and treating seasonal mood changes
Although there's no guaranteed way to prevent seasonal mood changes, there are effective treatments and coping strategies that can help, including:
- Talk therapy or counseling
- Medication, when recommended by a doctor
- Light therapy, using special lamps to mimic natural sunlight
- Exercise and staying active to boost endorphins and energy levels
- Social connection can help reduce feelings of isolation and improve mood
"The good news is that seasonal affective disorder is treatable," says Hill. "If you notice consistent mood changes that make it hard to function, reach out for support. You don't have to wait until things feel unmanageable. Help is available and early intervention can make a big difference."
Mental health resources
Many people living with both SAD and other mental health disorders struggle to find help or are concerned they won’t be accepted if they do choose to seek help. The good news is mental health resources are more easily available now than ever before.
If you or a loved one are struggling, know that help is available. Here are some key resources to know:
- Emergency medical services. Always call 911 if you believe the situation may be life-threatening
- National Suicide and Crisis Lifeline. Call or text 988 to speak with a trained crisis counselor. Visit 988lifeline.org to learn more.
- Substance Abuse and Mental Health Services Administration (SAMHSA). Call 1-800-662-4357 for treatment referral and mental health information. Visit their website for additional resources.
- National Alliance on Mental Illness (NAMI). Call the helpline at 1-800-950-6264. Visit their website to find additional mental health resources and support groups.
Talk to your doctor
Your primary care doctor is trained to care for your mental health along with your physical health. With proper treatment, many people can cope with or even recover from mental illness. Should you have any concerns about your mental health, talk to your doctor about treatment options.
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