10/14/2021
Simple Cure for Seasonal Affective Disorder
Fall, the leaves are turning and the days get shorter and cloudier. Then we start feeling down in the dumps and our energy level gets lower. This is commonly known as Seasonal Affective Disorder or SAD. It can be debilitating or just mild, either way all of us are touched by it, because we are mammals.
Let me back up a little bit, over 5 million years we evolved and our waking hours revolved around light, specifically natural daylight. We got up with the sun and went to bed with the sun, maybe we stayed up around the fire. During the spring, summer, and fall we hunted and gathered food. In the fall, the shorter days changed our metabolism so we could put on more fat to get us through the winter food shortages, just like bear, deer or any other mammal. Most of us blame it on holiday eating, but it is really nature. Then during the winter, shorter days, we slept longer, were more lethargic and slowly burned the fat off. Just like an old bear, probably just as grumpy too.
Fast forward to today. We still have that 5 million years of evolutionary, shorter day sleep drive, but societal pressure does not allow for it. We have to get up and go to work, get the kids off to school, go to the next meeting, etc. The result: SAD. That is that old bear coming through even though our day has completely changed because of electric light. You CANNOT change 5 million years of evolution over 150 years of electric light.
The old grumpiness/depression is triggered by shorter days, or lack of light, in particular a specific spectrum of light. There is a solution to this and it is relatively simple, but first a little science background. Our circadian rhythm, internal body clock, is set first thing in the morning based on specific spectrum of light entering our pupil. This light is picked up by a non-visual photoreceptor, ipRGC , in the back of our eye. It sends a signal to the brain and from there is distributed to every cell in our body. They all have time clocks. When you get up in the dark and it is cloudy all day, your time clock is not set properly. Your body still wants to sleep or just lay around and rest, yet you have to get on with life.
There is a solution to alleviating SAD in over 50% of the population. There are now LED light bulbs that mimic daylight. You want to be exposed to this light for at least a half an hour first thing in the morning to set your circadian clock. Put them in the kitchen, bathroom, or wherever you spend the first half hour.
The light bulbs are a daylight, 5000k or 6500k type of light. I prefer the 6500k light because it typically has more light at 481 nm and this is the most effective spectrum at setting your body clock. This light color is best first thing in the morning but it is also great all day, until evening. When exposed to this light, your body immediately shuts down melatonin production and starts cortisol production. It increases your heart rate, your breathing rate, your body temperature, cognitive thinking, visual acuity plus a whole host of other functions we are still learning about. It gets you ready for the day!
Getting you ready for the day versus getting you ready for sleep are two different things. You do not want to expose yourself to this light after 6 or 7PM. It will delay sleep onset. You want the warmer color like a traditional incandescent. Similar to the fire light we had before we went to sleep.
You do NOT have to buy a “happy light” for $150, you can buy daylight lights for $5-$10 at Home Depot or Lowell’s. There are now lights that will change color automatically based on time of day. I like to stick with the name brand lights, GE, Sylvania or Philips. Any of these and you can’t go wrong.
