LED or Fluorescent: Which Light is Best for Seasonal Affective Disorder (SAD)?

For individuals affected by Seasonal Affective Disorder (SAD), bright light therapy is a recommended treatment. This therapy can be effectively achieved using either LED or fluorescent lights. While both options can work, LED lights are often preferred due to their energy efficiency and durability. It is crucial to use lights that emit bright white light with a high color rendering index, which is available in both LED and fluorescent light bulbs. Additionally, it is recommended to use lights that mimic natural daylight, with a minimum of 10,000 lux.

Understanding Seasonal Affective Disorder and Light Therapy

The winter version of SAD is often linked to a lack of exposure to natural light. Despite its prevalence, similar lighting strategies can also be used to treat summer seasonal depression when the days are too long. Let’s delve into why light could be an effective cure for SAD.

Seasonal Trends in SAD and Lighting

Google Trends data reveals that searches for SAD peak around the end of October and do not significantly decrease until April or May. This trend mirrors the search patterns for LED lighting, though the LED data shows a noisier pattern. It is clear that people start thinking more about SAD and lighting in the fall and winter months.

The incidence of SAD is lower in states closer to the equator, such as Florida and Texas, and higher in areas further from the equator like Alaska. This is backed by the fact that Alaska has the shortest day lengths from all cities considered.

Location and Daylight

From Miami, Florida, with 10 hours 32 minutes of daylight, to Anchorage, Alaska, with only 5 hours 27 minutes, the shorter the length of the day, the higher the incidence of SAD. This suggests a strong correlation between the duration of daylight and the prevalence of SAD.

The Role of Light in Resetting the Circadian Rhythm

The circadian rhythm, or the body clock, is closely linked to light exposure. Our eyes contain photoreceptors called ipRGCs (intrinsically photosensitive retinal ganglion cells) that detect blue and green light between 440 and 570 nm. These photoreceptors send signals to the suprachiasmatic nucleus (SCN) in the brain, which helps synchronize the body clock.

Historically, humans were exposed to intense sunlight during the day and dim light at night. In modern times, we often suffer from a lack of morning sunlight and excessive blue light exposure from electronic devices, which can confuse the body clock.

SAD is considered a circadian rhythm disorder, at least in part. To treat SAD, we need to address the underlying circadian rhythm issues by using light sources that mimic natural day and night cycles.

Daytime and Nighttime Light Sources

For daytime use, you can find SAD therapy lamps on platforms like Amazon. These lamps should produce about 10,000 lux at a few feet distance. They are best used in the morning and early afternoon, and it is advisable not to look directly at these light sources. For nighttime, reduce blue light exposure by dimming displays and using low-blue light bulbs. For instance, Bedtime Bulb is a great option for reducing blue light in the evening.

Conclusion

SAD is more prevalent in the colder months and in more northern regions. It is a circadian rhythm disorder that can be treated with artificial light sources that mimic natural light cycles. Using SAD therapy lamps in the morning and early afternoon and reducing blue light exposure at night can help. Bedtime Bulb is an excellent solution for reducing blue light in the evening without compromising the quality of life.