At age 15.3 years, Mr. A, an African Canadian adolescent with no past medical problems and no personal or family history of obesity or eating disorders met the DSM-IV criteria for undifferentiated type schizophrenia. He was treated briefly with perphenazine and benztropine but was noncompliant with his drug regimen. At age 17.3 years, he was rehospitalized, and olanzapine treatment, 5 mg/day, was initiated (weight=150 lb; body mass index=20.9 kg/m2). Results of baseline laboratory tests, including thyroid indices and a computerized tomography scan of the head, were within normal limits, and positive psychotic symptoms were resolved. A third admission occurred at age 17.8 years, and Mr. A’s olanzapine dose was increased to 10 mg/day.
Mr. A then weighed 170 pounds; his weight had increased 20 lb over 6 months while taking olanzapine, 5 mg/day. Subsequently, his weight was recorded on four occasions over 7 weeks (index=170 lb, week 1=176 lb, week 3=182 lb, week 7=186.5 lb), indicating a gain of 16.5 lb after 7 weeks of treatment with olanzapine, 10 mg/day. Neither his diet, activity levels, nor any intercurrent medical conditions could account for his weight gain. His positive symptoms disappeared. After 14 months of olanzapine therapy (5.5 months at 5 mg/day; 8.5 months at 10 mg/day), his weight was 235 lb, and he had a body mass index of 32.9 kg/m2 (age=18.5 years). His dose of olanzapine was discontinued, and quetiapine treatment, 400 mg/day, was initiated, but it failed to control his positive symptoms. His symptoms remitted after switching to risperidone treatment, 2 mg/day. At the age of 19.5 years, his weight was 220 lb (body mass index=31 kg/m2), a decrease of 15 lb since he discontinued olanzapine.