"I have found that more physically engaging pursuits are the most psychologically rewarding, such as parkour and other athletic endeavours, tree climbing and swinging from branch to branch, slinging rocks for distance, running fast along the edge of the waves, launching atlatl darts as far as one can. Only through intense exercise do we feel truly alive. What modern man needs more of is exercise, intense, strengthening, enriching meaningful exercise, not repetitive workouts on weights machines, not running on a treadmill. Having friends to do these things with makes them all the more enjoyable and worthwhile. But that body must be taxed, sedentary lifestyles in my opinion, are a large factor in causing depression.[/QUOTE]
I agree with this 100% exercise definitely helped me out of depression when I was younger. Can be anything you like but like Wildranger says, taxing your system is the key, I also find getting a really good sweat on helps clear your nose etc, we've all seen footballers clear theirs mid game. Next tme you need to chop wood, stick an extra layer on and see how much you can (safely) chop in 10/20 mins.
Also take a lot of omega 3 oils, I could bore for ages with all the reasons why, but I. Short, they are anti inflamitary, indeed are the ONLY proven effective "natural" treatment for rheumatoid arthritis. There's also a lot of evidence that they help with depression, the brain is mainly made of fat and with modern diets lacking omega 3 and having far to much omega 6. And 9 which counteract omega 3, needs a boost in most people.
Like other people have said, a lightbox, vitamin D and a multi vitamin could well be a big help.
Finally, positive thinking, dwell on the things you have done each day which are good for you however small. The brain is like a muscle and can be trained to work/think however you wish with practice. When you get better at a job making feather sticks etc, it's because your brain has learned how to tell the muscle to move, so although people talk about "mucscle memory" you've really trained your brain. And the same is true when it comes to thinking.
I hope some of this makes sense! Lol and I hope you feel better soon
Mat