feline self-mutilation

Question
My kitten 8 months started attacking his tail about 1 month ago.  He has pulled much of the hair out and about 1/2 way up from end it is nothing but sores.  We had him to our vet a week ago and he is on antibiotics because of infection in area and also trying Bach Flower remedy, but he is still biting and clawing his tail.
"Willie" was abandoned by his feral mother @ 1 day old and raised by my daughter and I.  Now worried his mother knew something we didn't.  (She raised rest of litter of 4) I am really at a loss as how to help him.  He has a wonderful, loving personality.

Answer
I am not sure if he has already been tested for parasites, but if he has been on antibiotics then this may already have been done.  One possible explanation is Feline Hyperesthesia Syndrome, which is believed to be an obsessive compulsive disorder.  It usually affects cats 1-4 years of age but onset can be variable.  If the problem has continued I would suggest asking your veterinarian about the possibility of trying him on Phenobarbitol as an anti-obsessive treatment.  This may provide some relief to break the cycle and allow healing to occur.

My sincerest of apologies for the delayed response.