This is safe. I am not sure of rationale. 10mg. is very low dose (150mg is typical therapeeutic dosage, but that amount would be unsafe). Usually when I see this low dose added, it is for sleep or to see if it can provide addition medication benefit. If you are on the Prozac now (I see Celexa also) it was likely added to help counter the sometimes over stimulating effect of Prozac. In any event, can't hurt ay such a low dose and might help a bit.