claustrophobia /klôs′trə-/ [L, claustrum, a closing; Gk, phobos, fear] , a morbid fear of being in or becoming trapped in enclosed or narrow places. The phenomenon is observed more often in women than in men and can generally be traced to some traumatic situation involving enclosed spaces, usually occurring in childhood. Treatment consists of psychotherapy to uncover the cause of the phobic reaction, followed by behavior therapy, specifically systematic desensitization or flooding technique.