I have SAD. We moved to AZ nine years ago for my health and suddenly that went away. Now I only get it during the monsoon season when it can be cloudy for several days at a time. I'm ok for about two days and third day is bad, feel like my feet are concrete, no energy, dragging myself around, grumpy, and I hate it! But the weird thing is that when we moved, our Himalayan cat who was a total loner and wouldn't bond with anyone, suddenly began playing, purring, and romping with the other cats. It was amazing! I never gave a thought to animals having this, but seeing the difference in him has convinced me that why not? He also sleeps a lot more and is lethargic on cloudy days so there you go. And the lights didn't help me either Trinny!