Tomas Eriksson at Lund University (Sweden) conducted a small trial of the GnRH agent triptorelin (Trelstar) - constituting a special form of anti-androgen treatment - as therapy for OCD, finding improvement in five of six subjects.
Reference:
Eriksson T. Anti-androgenic treatment of obsessive-compulsive disorder: an open-label clinical trial of the long-acting gonadotropin-releasing hormone analogue triptorelin. Int Clin Psychopharmacol 2007; 22(1):57-61.