I know the depressed animal thing.
My daughter went off to college too this yr - over 11 hrs away - and my/her Siamese cat is just so depressed and needy. My cat lost her mate almost a yr ago & the absence of my daughter has just created the neediest cat.
My daughter will be home Friday night (YEAH) - perhaps yours too soon for the Thanksgiving break - it will be interesting to see if your furbaby improves once she comes home.
Did you talk with the vet about depression? Is there a possibility that she is allergic to her food? Have you changed something lately? I know my cat had food problems, throwing up, but finding a food without a lot of grains has totally changed things for her.