Seasonal Affective Disorder:
I was going to write about SAD syndrome for December Special Topics but with the dark mornings and early dusk I found it hard to raise much enthusiasm.
If you empathise with my feelings you probably suffer from the same problem. Suddenly you feel a bit flat and fed up, maybe not quite depressed but definitely more Scrooge than Marley. Apparently it's all to do with the pineal gland; even though it is positioned deep inside your head it is very sensitive to the hours of daylight and it releases a hormone that influences your mood.
As usual, with anything biological, we are all unique. The connection between daylight and misery varies enormously between individuals. We know that the pineal gland releases a hormone called melatonin, melatonin seems to influence the pituitary gland. Your pituitary gland influences all the other glands in your body (look up endocrine system if you want to know more), and the end result is changes in the chemical balance of your body that can make you feel miserable, can make your muscles ache, and can trigger depressive episodes. This variability of response is probably genetic but if you are susceptible you will not be in any doubt.
What can you do? Well if money is not a problem you can swap hemispheres - for example spend December to April in South Africa or Australia. I know some people who do this but for most of us this isn't a realistic option.
Here are some more suggestions:
Re-think your holiday plans. We are programmed to think of summer holidays; a couple of weeks in August or the end of July has been the norm for most people for decades. Why not stay home in the summer. Think about cutting the winter in two, have your main holiday in January instead; go for two or three weeks to somewhere bright. Give your pineal gland a treat.
Invest in some technology. You can buy products that mimic natural daylight. It might need a bit of experimenting to find what works best for you. Some people like a strong dose of bright light so a light box or full spectrum tube / bulb works well. Others respond better to a longer, gradual exposure something like a daylight alarm clock (otherwise called a dawn simulator or a wake up light) that begins to lighten an hour or more before "getting up time" so that your brain thinks it is Spring and not Winter.
Fight back with laughter. A good laugh will strengthen your immune system as well as toning your abdominal muscles. Many traditional activities that happen during the winter bring people together and encourage laughter and light-heartedness. And if the laughter and light-heartedness lead to dancing and over-exertion you can always rely on your friendly local osteopath to ease out the aches and pains a few days later.
Have a good Christmas.