To the Editor: Leuprolide is a synthetic luteinizing hormonereleasing hormone (LHRH) agonist used in the treatment of advanced prostate cancer. It is available as an immediate-release intramuscular injection, a depot suspension for intramuscular injection, and an extended-release suspension for subcutaneous injection. After a 45-mg dose of subcutaneous leuprolide, 99.1% of patients experience clinical castration by day 28, defined as serum testosterone levels < 50 ng/mL. 1 In addition to this decrease in serum testosterone levels, decreases in sex hormone-binding globulin and estradiol are also seen. 1,2 Although there have been reports 3,4 of emotional lability, depression, and anxiety with LHRH agonists, the data are not consistent. Furthermore, all published reports on psychiatric side effects of LHRH agonists have been exclusively in female patients. The package insert 1 of leuprolide depot subcutaneous injection does list anxiety, depression, and delusions as occurring in less than 5% of patients. Here, we describe a case of a 65-year-old man with no prior psychiatric history who developed manic and psychotic symptoms after receiving a 45-mg subcutaneous injection of leuprolide. This is the only case available in the literature that describes a male patient experiencing such severe psychiatric symptoms in association with leuprolide.Case report. Mr A, a 65-year-old white man, was brought into the emergency department by the police after they were called by his wife. She reported that he was extremely agitated, shouting profanities, threatening her, and accusing her of being schizophrenic. Over the last 3 to 4 weeks, he had been progressively sleeping less, only sleeping 1 to 2 hours per night immediately prior to admission. He had persecutory delusions regarding the Mafia and FBI. He was hyperverbal, had pressured speech, and was repeatedly quoting the Bible. Over the past several weeks, he had been displaying bizarre behavior, such as impulsively buying objects he had no use for and excessively spending money. He had also been irritable with his wife and using profanity, which was unusual behavior for him. At the time of admission, an accurate history could not be obtained