A simple treatment for SAD or ‘winter depression’ - About Health | Blog

Have you heard of seasonal affective disorder? Often called SAD, well, I think it is a complete misnomer, people who suffer from this have no disorder, it’s our environment that’s the disorder. I always feel more energised on bright sunny days with blue skies compared to grey August days. I always feel better in summer compared to winter, and its nothing to do with cold or the season. This effect is very common and probably dramatically under reported, the symptoms range from lethargy and irritability to depression. Of course, if you talk to a doctor they would traditionally say you are depressed and give you a script for a ‘so called’ antidepressant. The majority of the times these do not work, often cause harm and the levels of fraud in the research behind this class of drugs is remarkable, even by drug company standards. While many doctors now are onto the fraud behind many antidepressants, they are still the first line of treatment for most. My quick check suggests that in some parts of the world antidepressant prescriptions increase by up to 35% during the darker months in the year, and in that interesting fact alone lies a pretty big clue. The light we see every day is made up of a spectrum, if you see the colours shining off a DVD, or light splitting into a rainbow after passing through a drop of water on a leaf, or in fact, a rainbow you will understand that what we see as white light is actually made up of all the colours of the rainbow. Here is an example of light spectrum from daylight and artificial sources from popular mechanic’s magazine: As you will hopefully see, different light sources have a different spectrum of light. Of particular note is blue light. Most artificial sources have a light spectrum that is very different to daylight, even though we don’t really notice this as all light looks, well, light…some a bit more orange, some cooler and more blue… but none of this really matters to us when all we want to do is read a book. The second important aspect of light is how bright it is. The measure used is called LUX, or ‘Lumens per Square metre’ and a Lumen is how bright it is at the source. LUX is how bright it is where it is measured, i.e. where you usually sit and read in your lounge. A quick look at some tables indicates that daylight outside can hit 120,000 LUX and inside where I spend a lot of time sitting was a mere 30 LUX. That is an enormous difference, and to think it has no physiological affect is unlikely to me. I continued to read these tables and found house lighting should be 200 LUX and work 400, intense detailed work, maybe 800 LUX. The difference between outside and inside is so great it is surprising that we don’t notice more, but our eyes are extremely good at detecting contrast that they quickly adjust to conditions inside our artificial caves (houses).

And that’s where this story just starts.

Why is it that I felt less motivated and lethargic in grey weather, especially if it continued for a few days? The answer is to do with circadian rhythms and the serotonin/melatonin cycle. The circadian rhythm is your body’s natural daily cycle, the mornings we are most alert, most coordinated in the afternoons, highest blood pressure in the evening, sleepy at night etc. We are meant to make serotonin in the morning and when its daylight and melatonin at night when we want to sleep. Many people buy melatonin as a supplement (only on prescription in NZ) because its known as the sleep hormone. But you cannot buy a serotonin supplement, although various forms of precursor substances are available. If you have suffered from lethargy or winter depression called seasonal affective disorder, or SAD, you may have tried light therapy. That means buying a light box which is a special, very bright lamp that can hit your eyes with 10,000 LUX, usually from a stupidly short distance of around 16-20 cm. The sun on a bright day outside can easily be over 100,000 LUX, and you can be a more relaxing 149 million km away. If you use the lamp you are told to sit there, centimeters away for 30 minutes in the morning. People do this, and then they stop, as its very inconvenient. Other people are prescribed antidepressants, or they do both. Well, I went out and bought all the testing gear. I was fed up with the crappy weather and decided to find out why I felt so good when it was sunny and flat when it was cloudy for long periods. First I measured the LUX where I spend a lot of my time, 30 LUX, yip, just 30. So I took my LUX meter out on a cloudy day, that’s no sun peeking through… and got 6000 LUX. The second thing I did was check the spectrum of the light via measuring the colour temperature. Colour Temperature will be the focus of another article, it is basically an approximation of the light spectrum, a clear blue sky could be 17000K, fluorescent bulbs are 4000K, and a camp fire may be 1800K. All of this is relevant, in short the amount of blue light increases as you increase the colour temperature, and it decreases when you get very low. The camp fire example has almost no blue light compared to a cloudy day which has plenty. This blue light is incredibly important in the morning, and you don’t want any at all at night, say from 8.30pm, depending on when you go to bed. I didn't need a lightbox, I just started walking to work not wearing sun glasses, sitting by the window and I got plenty of blue light even on cloudy days, and it’s this blue light that is one of the easiest ways to make serotonin. Serotonin, as you may know, is the ‘get up and go’ hormone. To make it, you don’t even have to walk anywhere, just go sit outside for half an hour in the morning and you will make serotonin (no sunglasses!), and at the same time you will ensure you switch off melatonin, the sleep hormone. The problem is that when its grey and rainy we live inside, the rubbish lighting most homes have, even modern homes will not let you create enough serotonin and you will still have too much melatonin, and thus, people can feel anything from sluggish, annoyed and unmotivated to full on depressed. Well, after taking my measurements with light meters, measuring the approximate spectrum of the light, I started getting lots more natural light. I walked to work, stopped wearing sun glasses in the morning (wear a cap…takes about two days to adjust to the light I found) and I felt far more energised after about a week. The reverse is true as well, at night you need to get rid of blue light, and you can do this by wearing those very stylish orange safety glasses (about $20) if you need to. These will block all blue light and let you create melatonin so you can sleep easily. They are also very cool; your family will be impressed when you wear them around the house at night! In general, for SAD its 30 minutes at 10,000 LUX of white light, some companies make a blue light that is much more concentrated in blue light but much less bright overall. As I have tested, if you spent 30-60 minutes in the morning outside or beside the window you could get the required amount of light very easily without using a lightbox. But if you waver, you need to remember that it takes around a week, and even though you may think the grey light outside is no brighter than inside lighting, that’s not the case at all. In could be 200 times brighter and it’s just your eyes playing tricks on you. One more point, the light even on cloudy days can be 6000K, and that’s got plenty of that blue light as well, it does not need to be a blue sky! Daniel King MSc (hons)