Dr. Miles French
Despite the joys of the holidays, it’s not uncommon to experience a dip in mood during the darker months of the year. While this phenomena has been observed culturally for generations in parts of the world, we now have science to help us understand why some people become affected by the seasonal changes in light and weather. Seasonal Affective Disorder (SAD) is a type of depression (decreased mood) that follows a seasonal pattern, typically occurring during the fall and winter months when daylight hours are shorter. Although the exact causes of SAD are not completely understood, most experts believe it is a result of a combination of factors, including circadian rhythm dysregulation, hormonal changes, and decreased Vitamin D synthesis.
S.A.D. can manifest differently for different people, but often involves a combination of symptoms that typically revolve around depression and fatigue, but may also include symptoms such as loss of interest/motivation, unexplained sadness/hopelessness, difficulty concentrating, appetite or weight changes, and even becoming less social. And these changes can exist on a spectrum for many patients.
Whether you have already been diagnosed with S.A.D. or just want to support your mental health during the winter months, we can all benefit from these evidence-based practices to bolster mood in the winter.
- Maximize Natural Light Exposure: Spending time outdoors during daylight hours or sitting near windows can help regulate circadian rhythms and boost mood. Even on cloudy days, exposure to natural light is beneficial.
- Maintain a Regular Routine: Consistent sleep and wake times can help stabilize circadian rhythms, which are often disrupted in SAD.
- Exercise Regularly: Physical activity promotes the release of endorphins and supports overall brain health. Activities like walking, yoga, or strength training can be particularly effective for improving mood.
- Focus on Nutrient-Dense Foods: A diet rich in whole foods, including fruits, vegetables, whole grains, and lean proteins, supports overall health and may help regulate mood by providing essential nutrients.
- Consider Light Therapy: Bright light therapy is a first-line treatment for SAD. It involves daily exposure to a light box emitting 10,000 lux for 20–30 minutes in the morning. Studies show that light therapy can improve symptoms within 1–2 weeks.
- Vitamin D supplementation: Vitamin D plays a key role in serotonin and dopamine production, which are critical for mood regulation, and studies suggest that supplementation can improve symptoms of mild seasonal depression, such as low mood and fatigue. The recommended daily allowance (RDA) for Vitamin D varies by age and individual needs but generally ranges from 600–800 IU per day for adults. However, higher doses may be required for those with existing deficiencies. It’s important to consult with a healthcare provider before starting supplementation to determine the appropriate dose based on blood levels.
Naturopathic physicians are uniquely qualified to support our patients with SAD because we offer integrative, whole-person approaches that target the root causes of SAD, including addressing the nutritional, neuroendocrine, and psychological aspects of your health. We may recommend a combination of therapies, including botanicals, nutrient supplementation, lifestyle counseling, light therapy, or medication to meet your needs.
References
- Rohan KJ, Mahon JN, Evans M, Ho SY, Meyerhoff J. Seasonal affective disorder: Common questions and answers. Am Fam Physician. 2020;102(11):668-674.
- Lam RW, Levitan RD. Pathophysiology of seasonal affective disorder: A review. J Psychiatry Neurosci. 2000;25(5):469-480.
- Parker GB, Brotchie H, Graham RK. Vitamin D and depression. J Affect Disord. 2017;208:56-61. doi:10.1016/j.jad.2016.08.082
- Stewart AE, Roecklein KA, Tanner S, Kimlin MG. Possible contributions of skin pigmentation and vitamin D in a polyfactorial model of seasonal affective disorder. Med Hypotheses. 2014;83(5):517-525. doi:10.1016/j.mehy.2014.09.010
- Mayo Clinic Staff. Seasonal affective disorder (SAD): Diagnosis & treatment. Mayo Clinic. Published December 14, 2021. Accessed December 29, 2024.
- Kaviani M, Nikooyeh B, Zand H, Yaghmaei P, Neyestani TR. Effects of vitamin D supplementation on depression and some involved neurotransmitters. J Affect Disord. 2020;269:28-35. doi:10.1016/j.jad.2020.03.029
- CommonSpirit Health Staff. Vitamin D deficiency and seasonal depression: Understanding the connection between sunlight and mood disorders. CommonSpirit Health. Published March 4, 2022. Accessed December 29, 2024.