You say bite like it's a bad thing

Decided to visit a doctor to see if there is any treatment for my little nibbling issue.  First stop:  my general practitioner, Dr. O'Shin.  Wait in the waiting room nervously, walking up and down, down and up.  Tried not to bite myself, er, my nails.

When he finally sees me, he says I need an anti-depressant.  But, I say, I'm not depressed. Well, he says, this is what we start with when people have obsessive-compulsize behaviors.

Oh.  Is that what it is?  Then Dr. O'Shin recommends a therapist for me.  He says I probably can't cure onychophagia with medicine alone, there's maybe like a 1 in 3 chance.  But, now what?