Even in California I notice the seasonal effects, especially when it gets cloudy. This winter I experimented some with a SAD light (in particular the Phillips GoLite BLU) and better lighting (near a window at work, bed near a window at home, an alarm clock that turns on lights) and it made a big difference for me.
My experience is very similar. I use a "SunRay" lamp, and also take 5000 IU of Vitamin D3 every day. It doesn't completely eliminate seasonal symptoms for me, but makes a huge difference. Also, the more regularly I get exercise, the better.
