“Every winter it’s the same thing. I feel awful from late fall until late February. I’m sleepy all day, can’t sleep at night, depressed and grouchy. I really can’t help it.
I crave all carbs, mostly chips. I gain weight, but lose it in the spring. Weird!”
I hear this yearly. Symptoms vary, the misery doesn’t. People are relieved to find there’s help, even to know it has a name: Seasonal Affective Disorder or SAD. It affects around 5 percent of the population. Maybe not you, but likely someone you know has it. Here’s why it happens and what helps.
Seasons and our biology interact. Light controls the pineal gland which in daytime produces serotonin, a mood regulator. At night time, it produces melatonin, which puts us to sleep. In spring and summer, when there’s a sharp difference between daytime and night, the pineal readily switches production.
Two things change in late fall and winter. Days get shorter and the sun isn’t as bright as it is in spring and summer. The pineal of individuals with SAD doesn’t switch off melatonin production when the weaker sun comes up but continues with melatonin. It still “thinks” it’s night time.
The numbers tell us more
Light intensity is measured in lux. In summer at noon sunlight exceeds 100,000 lux. In winter here at our latitude just before Christmas 2012, direct sunlight only provided 13,000 lux. That’s intense enough for most people for proper pineal functioning.
Yet the next day was overcast and sunlight dropped to 2,500 lux, when SAD sufferers didn’t get enough daylight for their brains to shut off their melatonin production. They remained sleepy during the day, maybe seeking coffee to stay awake. Since they didn’t make enough serotonin, they also craved the ingredients in carbs to make more.
One cloudy day is bad for SAD but a straight week or two of them is intolerable.
Simple, right? If you lack light, then get more. The first choice is free: More direct sunlight. Sitting in the sun or taking a walk can both work, but without sunglasses, which can cut light up to 85 percent.
If that doesn’t work, there are special light boxes that simulate extra sunlight, available for under $75 on the Internet that provide 10,000 lux. Exposure can be as little as 15-minutes once in the morning or a couple of times spaced through the day depending on need. Light boxes come with instructions, and the bulbs in these boxes last for years.
It takes a few days before improvement and consistent use throughout the winter season, especially on overcast days, to obtain optimal results.
However, be cautious if you have eye problems, are bipolar, or take medicines that make you photosensitive. Check with your doctor before proceeding with light therapy. Side effects can occur, which small changes in distance from the light or duration of exposure usually correct. Side effects can include headaches, insomnia, or dry eyes, and in rare instances, a manic episode.
Light might not be the only issue. Vitamin D can decrease in winter, an issue easily measured with a blood test and corrected with a supplement. In some cases, an antidepressant is necessary, but usually the place to start is with natural light and, if necessary, adding artificial light.
If the extra light works, adjust your routine to start using it every year just before you normally get the symptoms to avoid even starting another year like those from your past.