Ketamine addiction following a single sub-anaesthetic ketamine treatment for acute suicidality in a psychiatrically multimorbid patient: case report.

This case report presents the case of a 25-year-old woman who developed ketamine addiction following a single sub-anaesthetic dose of intranasal ketamine in a pilot study investigating intranasal racemic ketamine for acute suicidality. She had a history of depression, obsessive-compulsive disorder, autism spectrum disorder and anorexia nervosa, and she had sporadically used alcohol and cannabis. Following the intervention, she reported a transient reduction in suicidal ideation but later sought illicit ketamine to recreate its calming effects on intrusive thoughts. Subsequently she also started abusing cocaine and 3-methylmethcathinone (3-MMC). Within weeks she had escalated to daily use, which led to financial distress, housing instability and a suicide attempt when access was cut off. Although she initially ceased use, she later relapsed into ketamine and cocaine addiction. This case highlights the addictive risk of ketamine, even in controlled settings. Given ketamine's rising use in psychiatric treatment, careful screening, monitoring and awareness of addiction potential are essential. Future research should evaluate patient-specific risk factors and dosing strategies to minimise abuse liability.