Seasonal Affective Disorder (SAD): A Gentle Light for Nurses During the Darker Months

Seasonal Affective Disorder and Nurses: Why It Matters

Nursing is a profession built on resilience, compassion, and adaptability — yet even the strongest caregivers can feel the emotional weight of darker seasons. As daylight fades during fall and winter, many nurses notice changes in mood, energy, and motivation. For some, these changes may signal Seasonal Affective Disorder (SAD), a form of depression that follows a seasonal pattern, most commonly emerging during the colder, darker months.

According to the National Institute of Mental Health (NIMH), SAD is more than the winter blues. It involves persistent symptoms that can interfere with daily functioning, relationships, and overall well-being.

What Is Seasonal Affective Disorder (SAD)?

Seasonal Affective Disorder is a type of depression that typically:

• Begins in late fall or early winter

• Improves in spring and summer

• Reoccurs around the same time each year

Common symptoms include:

• Persistent low mood or sadness

• Fatigue or low energy

• Oversleeping and difficulty waking

• Increased appetite, especially carbohydrate cravings

• Difficulty concentrating

• Social withdrawal

For nurses — especially those working long shifts, rotating schedules, or nights — limited exposure to natural sunlight can amplify these symptoms and disrupt circadian rhythms.

How Reduced Sunlight Affects Mood

Sunlight plays an essential role in regulating the body’s internal clock and brain chemistry. Reduced daylight exposure can:

• Disrupt circadian rhythms

• Lower serotonin levels (which affect mood)

• Increase melatonin production (which influences sleepiness)

The result can be a lingering heaviness that feels hard to shake — even for those who are used to pushing through challenging circumstances.

Light Therapy: A Research-Backed Support for SAD

One of the most effective first-line treatments for winter-pattern SAD is light therapy. This therapy uses a specially designed light box to mimic natural outdoor light and help regulate brain chemicals linked to mood and sleep.

How light therapy works:

• Uses a light box that emits about 10,000 lux, UV-free

• Typically used for 20–45 minutes each morning

• Helps reset circadian rhythms and improve mood

Many individuals notice symptom improvement within a few days to a few weeks when light therapy is used consistently.

Practical Light Therapy Tips for Nurses

• Use it in the morning: Morning exposure is most effective for regulating sleep-wake cycles.

• Build it into your routine: Use your light while journaling, drinking coffee, or preparing for your shift.

• Be consistent: Daily use during fall and winter offers the most benefit.

• Check with your provider: Especially if you have eye conditions or photosensitivity concerns.

(NIMH, 2025)

How Different Light Colors Affect Mood and Seasonal Depression

Our eyes don’t just help us see—they also play a decisive role in regulating mood and sleep. Special cells in the retina are sensitive to light, particularly blue light, which strongly influences our internal clock and melatonin production, the hormone that helps us sleep.

Because of this sensitivity, blue light can suppress melatonin even at lower intensities, making it more stimulating than regular white light. Some studies show that blue light therapy may be more effective at reducing depressive symptoms than white light, likely because of its higher energy and shorter wavelength. However, there’s an important balance to consider; exposure to blue light at night (such as from screens) may actually increase the risk of depression and disrupt healthy sleep patterns.

White light, which contains a mix of wavelengths, has long been used in light therapy for Seasonal Affective Disorder. It can help regulate circadian rhythms and improve mood, but it may not always be the most efficient option.

Emerging research suggests that green light may offer similar benefits—such as reducing melatonin and supporting circadian balance—while potentially being even more effective and gentler on the system.

Together, these findings are helping researchers refine light-based therapies for seasonal depression, guiding the development of more effective and personalized treatment tools. The takeaway is that light is healing, but how and when we receive it matter—inviting us to approach light therapy with intention, balance, and self-compassion.

(Wan et al., 2025)

Light therapy works best when paired with other supportive habits such as regular sleep schedules, gentle movement, nourishing foods, and time outdoors when possible.

Growing Gracefully Through the Darker Seasons

Caring for others starts with caring for yourself. Experiencing seasonal shifts in mood doesn’t mean you’re weak; it means you’re human. By recognizing the signs of SAD and embracing tools like light therapy, nurses can protect their mental health and continue to show up with compassion, clarity, and strength.

At Growing Gracefully with Love, we believe self-care isn’t optional — it’s essential. Even in the darkest seasons, small intentional practices can help you rediscover light.

References

National Institute of Mental Health. (2025). Seasonal affective disorder. NIMH. https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder

Wan, Y., Ding, J., Fan, M., & Huang, H. (2025). Effectiveness of visible light for seasonal affective disorder: A systematic review and network meta-analysis. Medicine, 104(27), e43107. https://doi.org/10.1097/MD.0000000000043107