obsessive compulsive behavior

I have a 2 yr old neutered male cat that I found as a stray when he was about 4 weeks old. He is well loved, gets lots of attention and interactive play. He has always been obsessed with sucking on my shirt before bedtime, which I attribute to his lack of nursing as a kitten. However recently he has started a behavior that is a bit alarming. He chases his tail round and round and bites the end of it so hard that he yowls. It's so bad that he actually has boo-boos on it now. I have tried to distract him by petting him or dangling a toy, but last night he actually nipped me in his frenzy to kill his tail (he has never bitten, scratched or even hissed at me before). He does this at other times of the day, but acts like he can't go to bed at night without going through his sucking/tail attack routine first. At first it was kind of amusing, but it's gotten out of hand. He is hurting himself, and it's no longer a game, he actually seems afraid of his tail when he's going through the behavior. Other times he is fine and totally ignores the evil tail following him around. He's never been a smart cat, and I'm wondering if he suffered a little brain damage from poor nutrition as a baby. Any suggestions on how to help him?

It sounds pretty normal for a cat who has OCD similar to humans. It really doesn't have much to do with anything other than a chemical imbalance. The alternate to him biting his tail is to think about medication. There's several your vet would be able to prescribe. The 2that are used most often are Prozac and Buspirone.

Thats interesting. I have never heard of such a thing in cats.

Sandie's advice is very sound, and I would definitely seek a vet's advice. For the possibility of instant relief... try a little citrus compound on his tail... bitter orange is one that comes to mind.