Has she been to the vet recently? I think before I started to supplement, I'd have a vet look her over to make sure it isn't a physical problem, like thyroid or kidney. Once you've ruled out health issues, then I'd try supplements. A year seems like a long time to still be stressed--everything should be routine by now, you'd think...though who knows what goes on in the minds of cats?
Could it be weather? Has it been dry there?
We've got dogs, and very little cat experience, but salmon oil works well with the dogs. I know people use the salmon oil with their cats, as well, with good success.