all in your head

Anyone else feeling down this time of year?  Has anyone else been told by their doctor that they have SAD or seasonal affective disorder? 

I was told this by my doctor years ago.  I usually can get through the holidays but then come January and February, and I am done.  I feel like I am in a time warp and all the days blend into one.  I feel lethargic and not much makes me happy.  I am aware of it and I consciously try to open the shades to let the sun in whenever it decides to make an appearance. 

But some days, I just feel down.  I feel as though I could (and sometimes do) cry for no reason other than to cry.  Often times this helps, but other times, I just feel like I am being ridiculous. 

Today, and not for the first time, I was told that this disorder and more specifically, depression, is all in my  head.  Literally.. that all I need to do is make the decision to NOT be depressed or sad and it will change.  To some extent, I agree.  We all make choices.  We can choose to allow someone or something bother us or not.  But I also think that if you are predisposed whether by genetics or life experience to something, there is only so much you can do. 

How do YOU feel about this?  What do you do to combat the winter blues, or SAD?