Ketamine Use Disorder and Entrenchment of Delusional Beliefs: A Case Report

Background: Ketamine has gained increasing attention for its therapeutic potential, yet concerns remain regarding its misuse and the associated complications of its use. Ketamine use and ketamine use disorder can induce psychotic symptoms, but the persistence of such symptoms with chronic use and effective treatment of these symptoms is poorly characterized. Although case reports of ketamine use and medical and psychiatric consequences exist in the literature, there is limited evidence regarding the treatment of ketamine use disorder (KUD). Case Summary: We present the case of a 36-year-old man who developed persistent delusional beliefs and medical complications over 2 years of heavy, chronic ketamine use. In the absence of any prior psychiatric diagnoses other than alcohol use disorder, he met DSM-5-TR criteria for KUD. His beliefs were primarily grandiose and hyper-religious in content, incorporating fringe online content. Although there was a limited impact on his functioning, his beliefs were maintained in delusional intensity. Written informed consent was obtained from the patient. Conclusions: This case report illustrates a manifestation of enduring delusional beliefs in the setting of chronic ketamine use and other important medical sequelae of its use. Limited literature exists concerning the treatment of ketamine use disorder or related psychotic symptoms, and there is a need for standardized treatment guidelines so interventions may be provided promptly to prevent serious psychiatric and medical complications.