How effective is citalopram (Celexa) for treating obsessive compulsive disorder (OCD)?

It's effective. Studies indicate SSRIs including fluvoxamine (Luvos) sertraline (Zoloft), fluoxetine (Prozac), citalopram (Celexa) and paroxetine (Paxil) can reduce OCD symptoms by 40-60%. SSRIs may also be used in combination with two empirically validated psychotherapies, Exposure plus Response Prevention and Cognitive Therapy. Ask your doctor for more information about your options.