By: Mark Pettus, MD
As the days grow shorter and our exposure to natural sunlight decreases, many of us fall into a cycle of what some call winter depression, a general feeling of sadness, and diminished energy that can have a significant effect on our physical and mental health, interpersonal relationships, work performance, and overall quality of life. In clinical terms, it’s a phenomenon known as fall-onset Seasonal Affective Disorder (SAD); a condition experienced in varying degrees by at least one of every four of us, although experts suspect the actual incidence may be far higher than the number of cases reported. The condition can be further compounded by the stress of the winter holidays.
Like every other living thing, the human body is subject to what is known as circadian rhythm; a biological process that’s essentially an internal clock regulating our 24-hour sleep-wake cycle. Those rhythms are affected by light. The change of seasons, particularly from fall into winter, with its later sunrises and earlier sunsets, can disrupt that rhythm, draining our energy and our mood. People experience this effect in different degrees; some barely notice it, some simply tolerate it, while others are profoundly affected and may need some sort of treatment, sometimes medication, to help them through.
The good news is that no matter how mild or severe your winter-months SAD condition may be, there are some highly-effective, simple, and inexpensive ways to help treat the condition – by artificially recreating the natural light exposure we experience during spring and summer.
Full-Spectrum Light Box
These are compact devices, plugged into a regular outlet or a laptop using a USB cord, which recreate the light quality and intensity of a late spring or early summer sunrise. Whereas a normal lightbulb emits some 800 lumens, a full-spectrum light box emits some 10,0000 lumens. Spending 20 to 30 minutes near a light box (a few feet away with access to open eyes) while you’re reading the morning paper, checking your emails, or having breakfast is an easy, yet powerful, way to boost your exposure to light and your mood. The devices are readily available online or in stores for less than $50, slightly more if you want added features. While a full-spectrum lamp will not raise your Vitamin D levels, it will serve as an important entrainment tool to coordinate your circadian “on-switch”.
These devices, similarly sized and priced, also mimic the spring-summer sunrise, but are set on a timer in your bedroom, gradually increasing in intensity before you wake and as you rise. Some people prefer the dawn-light simulator. Others prefer the full-spectrum light box. Many find the combination of both is the ideal solution.
Reducing Exposure to Blue Light
On the opposite end of the light-exposure spectrum, some lights are not good for you late in the day. The blue light from our smartphones, laptops, and similar sources also disrupt our circadian rhythm. After sunset, if we’re exposed to light that mimics sunrise, our brains think it’s anywhere from 6 to 8 a.m., and that’s a problem for our mood, our readiness for sleep, and our health, in general. It is recommended that blue-screen screen filters are used or that such devices are set up to automatically reduce the emission of blue light. In addition, having warmer 2500-2800k LED or halogen lighting in rooms where you spend time after dark, e.g. family room or bedroom, will limit excessive blue light frequencies and provide light quality that represents evening natural light.
Managing exposure to light, whether you’re increasing or reducing it, is a well-proven method of reducing the effects of Seasonal Affective Disorder. But light alone is by no means the only answer. When it comes to our mood and our overall physical and mental well-being, many other converging factors – including our diet, level of physical activity, the state of our personal relationships, our work satisfaction – can deeply influence our state of mind and quality of life. To be truly healthy, we need shine the light on all of those, together.
Mark Pettus, MD, is the Director of Wellness and Population Health Berkshire Health Systems.