Street ketamine use and differential risk of suicidality among adults in Taiwan.
Yen-Chun Kuo, Sheng-Chang Wang, Chuan-Yu Chen
Harm Reduction Journal September 29, 2025 DOI: 10.1186/s12954-025-01308-7 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 379 |
| Population | Illicit ketamine users and non-users in northern Taiwan |
| Topics | Ketamine Esketamine |
| Keywords | Anxiety disorders Mental health Suicidality Suicide risk |
| Key findings | Illicit ketamine use, especially recent use, is strongly associated with increased suicidality, with past-month suicidality four times higher among recent users and 3.4 times higher among past users compared with non-users. |
Abstract
The misuse of ketamine, a dissociative anesthetic, has surged sharply in popularity across East and Southeast Asia and Oceania. This study aimed to evaluate the association between recent patterns of ketamine use and the risk of suicide in northern Taiwan. Illicit ketamine users were recruited through network-based sampling from 2015 to 2017, along with a comparison group of individuals who never used ketamine. Data on sociodemographics, drug use history, psychiatric disorders, and suicide risk were collected by trained psychiatric nurses. Participants were categorized into three groups: non- (n = 132), past (no ketamine use for ≥ 1 year; n = 80), and recent users (use in the past year; n = 167). Suicide risk, assessed by six items in the Mini-International Neuropsychiatric Interview, was classified as "no," "low," or "middle/high." Polytomous logistic regression and multivariate analyses were applied for risk estimation. Street ketamine users disproportionately experienced higher mental health disorders (e.g.,major depressive disorder), disadvantaged socioeconomic status, involvement in legal issues, and lifetime suicide attempts (25%). The prevalence of middle to high suicide risk was notably higher among recent (10.8%) and past (5.0%) ketamine users, compared with people who had no ketamine use history. Past-month suicidality was four times higher in recent users (95% CI 1.35-12.27) and 3.4 times higher in past users (95% CI 1.01-11.45). Excess risk associated with recent ketamine use manifested exclusively in suicidal ideation. Illicit ketamine use is strongly linked to increased suicidality, especially among recent users. Even past users remain at higher risk, highlighting the importance of integrating suicide risk assessments and targeted interventions in community-based alcohol and drug services.
Comparable studies
Other observational and cohort studies on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Taming the Ketamine Tiger Volunteers from a prison population | 2010 | Observational study | n = 20 |
| Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin Humans | 2017 | Observational study | |
| Disruption of Frontal–Parietal Communication by Ketamine, Propofol, and Sevoflurane Surgical patients undergoing induction of anesthesia with intravenous ketamine | 2013 | Observational cohort | n = 30 |
| Do the dissociative side effects of ketamine mediate its antidepressant effects? Treatment-resistant inpatients with major depressive disorder or bipolar disorder | 2014 | Observational cohort | n = 108 |
| Concomitant BDNF and sleep slow wave changes indicate ketamine-induced plasticity in major depressive disorder Patients with treatment-resistant major depressive disorder | 2012 | Observational cohort | n = 30 |
Citations in the library
Cites 9
- Ketamine for rapid reduction of suicidal thoughts in major depression: a midazolam-controlled randomized clinical trial American Journal of Psychiatry December 5, 2017
- Ketamine Has Distinct Electrophysiological and Behavioral Effects in Depressed and Healthy Subjects Molecular Psychiatry February 27, 2018
- Ketamine for the acute treatment of severe suicidal ideation: double blind, randomised placebo controlled trial British medical journal February 2, 2022
- The landscape of ketamine use disorder: Patient experiences and perspectives on current treatment options. Addiction April 28, 2025
- New psychoactive substances in Taiwan: The current situation and initiative for rational scheduling. Journal of Food and Drug Analysis March 15, 2021
and 4 more in the library