It would have to be a one-on-one, maybe even a sort of "rescue" therapy-of-last-resort sort of thing. Or it might come at a later stage of their recovery, sorta like Ziva taking Gibbs' collar while she worked out her own issues. For that matter, Gibbs is providing "therapy" for all his subs. A place of safety; a refuge from a world they're not equipped, for one reason or other, to move through without being hurt or hurting themselves.