Case 1. Mr. A, a 36-year-old Caucasian man with an 18-year history of recurrent command hallucinations, suicide attempts, paranoid delusions, severe depression, and alcohol dependence, had been in remission for 1 year on a regimen of fluphenazine decanoate, 37.5 mg i.m. every 2 weeks, and nefazodone, 100 mg p.o. at bedtime. The patient experienced coarse truncal and extremity tremors. Four days after the addition of olanzapine, 10 mg/day p.o., to his regimen, his tremors had noticeably diminished; by day 7, they were no longer apparent. Without further medication adjustment, the tremors had not returned after 26 weeks.

Case 2. Ms. B, a 25-year-old African American woman with a 2-year history of recurrent paranoid ideation, violent behavior, psychotic depression, and mania, with intercurrent marijuana, heroin, and "crack" cocaine abuse, had been in remission for 1 year on a regimen of fluphenazine decanote, 25 mg i.m. every 2 weeks; fluphenazine, 7.5 mg p.o. at bedtime; and divalproex sodium, 1000 mg p.o. twice a day. She had developed coarse hand tremors that disappeared within 7 days of the addition of olanzapine, 10 mg p.o.; her tremors had not returned after 21 weeks without other medication changes.

Case 3. Ms. C, a 34-year-old African American woman with a 20-year history of recurring severe thought disorganization or mania, had been in remission for 1 year on a regimen of haloperidol, 20 mg p.o. at bedtime; lithium carbonate, 300 mg p.o. twice a day; and divalproex sodium, 750 mg p.o. twice a day. She had unsightly coarse circumoral and hand tremors, not relieved with lithium discontinuance. Her tremors disappeared 1 week after initiation of treatment with olanzapine, 10 mg/day p.o., without other medication adjustments; her tremors had not returned after 20 weeks.