THE PATIENT, a 24-year-old nurse, was first seen on Oct. 2, 1959. She was desirous of breaking her addiction to methyprylon (Noludar), a drug which she had been using for 18 months. During the past year, she reported using a minimum of 25 300-mg. tablets (7,500 mg.) per day. Frequently her intake reached 40 of these tablets (12,000 mg.) per day. She had used barbiturates to excess from 1953 to January, 1958, when, in a self-imposed attempt to terminate her addiction to these materials, she substituted methyprylon. It is significant that she could replace the barbiturates with methyprylon, despite their dissimilar chemistry (see figure). Report of a Case The patient's history included a diagnosis of pernicious anemia in 1952 which was "confirmed" by the presence of achlorhydria. She took vitamin B12 orally and by injection for a few months, and has had no evidence of anemia or combined-system