A Brain Chemical Linked to Schizophrenia Made THC's Impairing Effects Worse in Mice

The metabolite kynurenine amplified THC-induced sensorimotor impairment and classic behavioral effects in mice, possibly by increasing THC blood levels.

Bilel, Sabrine et al.·Progress in neuro-psychopharmacology & biological psychiatry·2025·Preliminary EvidenceAnimal StudyAnimal Study
RTHC-06064Animal StudyPreliminary Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

Mice given kynurenine before THC showed significantly worse sensorimotor responses, greater motor impairment, and deeper hypothermia compared to THC alone. Kynurenine also increased blood levels of THC and its psychoactive metabolite 11-OH-THC.

Key Numbers

Brain kynurenic acid levels significantly increased 1 hour after kynurenine administration; THC and 11-OH-THC plasma levels were higher in kynurenine-pretreated mice; kynurenine amplified THC effects on motor tests (bar test, drag test, rotarod) and hypothermia but not pain response

How They Did This

Adult male mice received THC (30 mg/kg) and kynurenine (20 mg/kg) alone or combined. Researchers measured body temperature, pain responses, motor activity, sensorimotor function, brain kynurenic acid levels, and plasma THC concentrations.

Why This Research Matters

The kynurenine pathway is dysregulated in schizophrenia, and THC can worsen psychotic symptoms. This study suggests a biological mechanism linking the two: elevated kynurenine may amplify THC's effects, potentially explaining why people with schizophrenia are especially vulnerable to cannabis-related harm.

The Bigger Picture

Understanding why some people are more vulnerable to THC's negative effects is a major research priority. This study points to the kynurenine pathway as one biological factor that could amplify THC-related impairment, with particular relevance for people with schizophrenia.

What This Study Doesn't Tell Us

Male mice only, high THC dose (30 mg/kg), kynurenine-THC interaction may be partly pharmacokinetic rather than pharmacodynamic, cannot confirm mechanism applies to humans

Questions This Raises

  • ?Do people with elevated kynurenine levels experience stronger THC effects?
  • ?Could kynurenine pathway activity predict individual vulnerability to cannabis-induced psychosis?
  • ?Would lower THC doses show the same interaction?

Trust & Context

Key Stat:
Kynurenine pretreatment increased both THC blood levels and its behavioral effects in mice
Evidence Grade:
Single animal study with male mice only; first to demonstrate kynurenine-THC interaction on sensorimotor function
Study Age:
Published 2025
Original Title:
Kynurenine amplifies tetrahydrocannabinol-induced sensorimotor impairment and classic "tetrad" effects in mice.
Published In:
Progress in neuro-psychopharmacology & biological psychiatry, 138, 111342 (2025)
Database ID:
RTHC-06064

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

What is kynurenine and why does it matter for cannabis?

Kynurenine is a metabolite in a brain chemical pathway that's overactive in schizophrenia. This study found it amplified THC's impairing effects in mice, suggesting a biological reason why some people may be more vulnerable to cannabis.

Did kynurenine change how THC is processed in the body?

Yes. Mice pretreated with kynurenine had higher blood levels of both THC and its psychoactive metabolite 11-OH-THC, suggesting the interaction may be partly about how the body processes THC.

Read More on RethinkTHC

Cite This Study

RTHC-06064·https://rethinkthc.com/research/RTHC-06064

APA

Bilel, Sabrine; Corli, Giorgia; Tiziani, Edoardo; Chirenti, Daniele; Dall'Acqua, Stefano; Comai, Stefano; Ferraro, Luca; Marti, Matteo; Beggiato, Sarah. (2025). Kynurenine amplifies tetrahydrocannabinol-induced sensorimotor impairment and classic "tetrad" effects in mice.. Progress in neuro-psychopharmacology & biological psychiatry, 138, 111342. https://doi.org/10.1016/j.pnpbp.2025.111342

MLA

Bilel, Sabrine, et al. "Kynurenine amplifies tetrahydrocannabinol-induced sensorimotor impairment and classic "tetrad" effects in mice.." Progress in neuro-psychopharmacology & biological psychiatry, 2025. https://doi.org/10.1016/j.pnpbp.2025.111342

RethinkTHC

RethinkTHC Research Database. "Kynurenine amplifies tetrahydrocannabinol-induced sensorimot..." RTHC-06064. Retrieved from https://rethinkthc.com/research/bilel-2025-kynurenine-amplifies-tetrahydrocannabinolinduced-sensorimotor

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.