20mg even 40mg will help you see some diference with depression. Hair pulling? It is called "tricho" something (poor memory) I am not sure about the relation of that and celexa, I've been on celexa, but not for any OCD type behaviour(s), it was primarily for depression. Welcome to the forums, you will meet a lot of nice, supportive people here.
For your well being, I hope you are being treated by a pdoc and not a GP for this disorder. GP's are best at their field, but Psychiatrists cannot be replaced by seeing a GP.
Lots of luck, please take care
"darkeyes"

In giving advice seek to help, not please your friend
SOLON