“In the depth of winter, I finally learned that within me there lay an invincible summer.” — Albert Camus

Written by Dr. Elizabeth Brewer, Psy.D., Dynamic Psychotherapy Center
November 11, 2025


Even in Southern California, where the sun graces us most days of the year, many people notice subtle changes as the light shifts. The sun sits lower, mornings arrive more slowly, and our internal rhythms respond. Seasonal Affective Disorder (SAD) reminds us that mood and biology are deeply linked to light itself.

The Science of Light and Mood

Our circadian rhythm, our body’s internal 24-hour clock, governs sleep, hormones, and mood. When daylight decreases, melatonin begins producing earlier, while serotonin levels may dip. The result can be fatigue, carbohydrate cravings, and a low mood. Recent studies show that these seasonal changes influence not only how we feel but also gene expression and hormone regulation.

Shining Light on Treatment

Because SAD stems from circadian misalignment, healing often begins with reconnecting to light. Morning bright-light therapy has been shown to relieve symptoms of seasonal depression. Cognitive Behavioral Therapy for SAD (CBT-SAD) offers another effective approach, helping individuals shift unhelpful thought patterns and strengthen resilience through the darker months.

Gentle lifestyle adjustments can also help restore the body’s rhythm:

  • Morning Light Ritual: Spend 10–15 minutes outside soon after waking.
  • Evening Wind-Down: Lower lights and screens an hour before bed.
  • Steady Rhythm: Keep consistent sleep and wake times, even on weekends.

A Gentle Invitation to Presence

If your energy wanes or your emotions feel heavy as the days shorten, know that it’s not “all in your head.” Your entire system is responding to nature’s rhythm. You might notice yourself withdrawing from social plans, finding it harder to concentrate, or feeling less motivated to engage in things that normally bring joy. Healing involves bringing your inner world back into alignment with the outer one.

Winter, even in a bright place, invites us inward, not as punishment, but as recalibration. Light will return, and so will the rhythms that make you feel most alive.

Call to Action

If you notice these seasonal shifts affecting your mood or daily life, you don’t have to navigate it alone. Therapy can help you find balance and reconnect with your inner light. Schedule a consultation today.



References

Levy, E. et al. (2023). Circadian Rhythms and Mood Disorders: Time to See the Light. Neuron, 111(9), 1356–1371. https://doi.org/10.1016/j.neuron.2023.04.003

Partonen, T., & Magnusson, A. (2020). Seasonal Affective Disorder: An Overview of Assessment and Treatment. Frontiers in Psychiatry, 11, 69. https://doi.org/10.3389/fpsyt.2020.00069

Rohan, K. J., Mahon, J. N., & Lenoir, M. (2019). Randomized trial of CBT-SAD versus light therapy for winter depression: Efficacy and durability. American Journal of Psychiatry, 176(6), 435–445. https://doi.org/10.1176/appi.ajp.2018.18040478

The Guardian. (2025, November 2). How scientists are shining light on the biology behind seasonal affective disorder. https://www.theguardian.com/society/2025/nov/02/how-to-beat-the-winter-blues-seasonal-affective-disorder

Wu, L., Zhao, Y., & Chen, J. (2025). Effectiveness of visible light for seasonal affective disorder: A meta-analysis. Medicine, 104(7), e23876. https://journals.lww.com/md-journal/fulltext/2025/07040/effectiveness_of_visible_light_for_seasonal.76.aspx