One of my cats was very attached to me. When we first got her and one other cat they where bot hwithdrawn because their previous owner had just died. But now they are happy cats and love us. Liek I said one of them was attached to me I would always say I had a second shadow. But this is my second year and college so I had to move back up to school and for some reason this year she is having a harder time. I have noticed that she is "hiding" and very withdrawn from the family. I have even noticed some weight loss. When I am home she doesn't even sleep in my bed anymore. Sometimes its like I don't even exist.

she's probably depressed, but get her to a vet to rule out any medical condition

Sudden personality changes and weight loss in a cat can mean a lot of things and most of them aren't good. You need to get your cat to the vet ASAP and find out what's going on. It would also be a good idea to take one of your parents or another family member who has been living with the cat while you've been away at school so that they can answer the vet's questions about the cat's day-to-day behavior.
Good luck. I hope everything works out with your kitty.

Try to go out of your way to make her feel she's still noticed and loved. Physical petting and quiet talking can do wonders. If a cat bonds to one person really strong they don't know that they went to college, they just think the person died because they're not there anymore. You have to help her feel like things are ok.
Seek her out four or five times a day, say something to her, touch her, pet her. She needs to know she's still loved.

This is the cat's way of saying that you betrayed her by abandoning her. You can only deal with it. The poor cat has no option to tell you off and she has no idea what a college is. So just be ultra kind when you can and let her come to you on her terms. If the weight loss is marginal or she is still in the healthy weight range that is not a problem. A lot of cats fine down a bit as they get older. If you are concerned by all means have her go to the vet. Check for worms and any other conditions. But mostly, ask your mother is the cat getting enough human contact when you are not there. She may have chosen to bond to someone else in the family as she sees you as having walked out on her.
Best wishes to you and the kitty.
Cheers
Lisa

Well my first thought is that she needs a visit to the vet to make sure she's not ill. Cats will "hide" when they don't feel well. Secondly, she is probably angry with you and showing you that if you abandoned her and don't need her, she doesn't need you.

Cats are very emotional creatures, and they are very attached to their people. And they suffer grief and can become depressed. This cat may very well need to have its central person around all the time, or most of the time, and given the fact that she has now, from her perspective, lost two of her mainstay people sequentially, she could no-kidding be suffering a depression. Cats do respond to some of the same human antidepressants prescribed for humans, like Prozac.
You need to consult with a vet about this, and you would want to deal with a vet who will take you seriously, as some will not. But you also need to see to it that someone in your family takes up the slack for you in your absence, or else you need to find a permanent home for this cat that is stable, where her main person isn't likely to die too soon, and won't be absent from home for an extended period. If someone in the family is willing to make her feel special and give her the extra attention, perhaps that and an antidepressant will get her over this hump.
But you really do need to consult with a vet, first, to rule out any organic basis for her behavior. A cat that does not feel well will withdraw and lose weight. If the behavior is psychosomatic, then antidepressants and attention or a new home might be warranted.
Get her in to the vet.

Please take her to a vet a.s.a.p. Weight loss and acting withdrawn are symptoms of illness or depression. The sudden absence of a familiar person can be very distressing to cats, particularly as she was very attached to you emotionally. Some cats pine and refuse to eat to the point of making themselves critically ill. In severe cases they've had to be euthanised because prolonged fasting results in liver damage.
The web article "When Cats Grieve" by Sarah Hartwell explains this emotion in more detail and has information that may help your family reassure her whilst you are away from home.
http://www.messybeast.com/cat-grief.htm

Sudden weight loss could mean he might have worms- or some other sickness. I'd bring him to the vet- and explain his new actions. Also- it could just be a phase. I know it sounds weird. But my cats went through this "teenager" phase- as I call it, where they wanted nothing to do with me. They had previously slept on the end of the bed everynight. But- after about a year they grew out of it and now its back to the way they used to be.
Also- when you move- it is hard on cats-they can get stressed. I would suggest maybe getting a Feliway plug in.
Feliway is a product that contains the synthetic version of the naturally occurring facial pheromones of cats.
A pheromone is a chemical marking agent excreted by cats to mark their territory and can server as an attractant to the opposite sex. Feliway has many uses, including, but not limited to, reducing or eliminating the following behaviors:
Urine marking
Aggression
Facial marking
Stress reduction at the veterinarian, groomer, kennel, or while traveling
Scratching on vertical surfaces
Hope any bit of this helps!

Try playing with it with a string or ball. Or you could get another cat so the one you have now will have a cat friend.

It's possible the weight loss could be a reaction to your inattention from moving out, but bring her to the vet and have her checked out. Worms is one possibility, but another very common ailment in cats is hyperthyroidism. That causes them to lose weight and they need medication on a daily basis. It's manageable, but shouldn't be ignored. Have your cat checked to be sure there isn't some sort of health issue causing the weight loss and disinterest in interaction.