A Gene Variant Affecting Dopamine Breakdown Influenced THC Blood Levels in Pain Patients

The COMT 680 T>C genetic variant significantly influenced THC plasma levels in chronic pain patients using medical cannabis, while BDNF levels correlated with cannabinoid concentrations.

Manca, Alessandra et al.·Journal of xenobiotics·2025·Preliminary EvidenceObservational
RTHC-07037ObservationalPreliminary Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Preliminary Evidence
Sample
N=58

What This Study Found

The COMT 680 T>C genetic variant significantly influenced plasma levels of THC (p = 0.017). Patients using inhaled cannabis had significantly different BDNF (p = 0.004) and IL-10 (p = 0.009) levels compared to those using cannabis decoction. Both BDNF and neurofilament light chain levels correlated with cannabinoid concentrations.

Key Numbers

N = 58 patients. COMT 680 T>C variant associated with THC levels (p = 0.017). IL-10 difference by route (p = 0.009). BDNF difference by route (p = 0.004). 47 decoction users, 11 inhaled cannabis users.

How They Did This

Observational study of 58 patients with neuropathic or chronic pain treated with medical cannabis (47 decoction, 11 inhaled; 30 high-THC, 28 reduced-THC/CBD). Cannabinoid plasma concentrations were measured by UHPLC-MS/MS. Genetic variants were assessed by real-time PCR. Inflammation biomarkers analyzed by ELISA and neuronal markers by Single Molecule Array.

Why This Research Matters

This study provides early evidence that genetic makeup can affect how the body processes medical cannabis. If certain gene variants predict higher or lower drug levels, this could eventually help personalize cannabis dosing for pain patients.

The Bigger Picture

Pharmacogenomics is transforming how many drugs are prescribed, but cannabis has largely been left out of this movement. Studies like this begin to build the foundation for genetically informed cannabis dosing.

What This Study Doesn't Tell Us

Very small sample size (58 patients, only 11 inhaled). The imbalanced group sizes limit statistical power. Multiple biomarkers were tested without correction for multiple comparisons. This is a preliminary finding that requires replication in larger cohorts.

Questions This Raises

  • ?Should COMT genotyping be considered before prescribing medical cannabis?
  • ?Do the observed biomarker changes have clinical significance for pain outcomes?

Trust & Context

Key Stat:
COMT gene variant significantly affected THC plasma levels (p = 0.017)
Evidence Grade:
Small observational study with only 58 patients. Findings are hypothesis-generating and require replication in much larger cohorts.
Study Age:
Published in 2025.
Original Title:
COMT Genetic Variants and BDNF Level Associations with Cannabinoid Plasma Exposure: A Preliminary Study.
Published In:
Journal of xenobiotics, 15(3) (2025)
Database ID:
RTHC-07037

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

What is COMT and why does it matter for cannabis?

COMT (catechol-O-methyltransferase) is an enzyme that breaks down dopamine and other catecholamines. Variants in this gene affect enzyme activity and appear to influence how the body processes THC, potentially affecting drug levels and effects.

What is BDNF?

Brain-derived neurotrophic factor is a protein that supports nerve cell survival and growth. Its levels correlated with cannabinoid concentrations in this study, suggesting cannabis may influence neuronal health markers.

Read More on RethinkTHC

Cite This Study

RTHC-07037·https://rethinkthc.com/research/RTHC-07037

APA

Manca, Alessandra; Valz, Cristina; Chiara, Francesco; Palermiti, Alice; Mula, Jacopo; Soloperto, Sara; Antonucci, Miriam; De Nicolò, Amedeo; Luxardo, Nicola; Imperiale, Daniele; Vischia, Flavio; De Cori, David; Cusato, Jessica; D'Avolio, Antonio. (2025). COMT Genetic Variants and BDNF Level Associations with Cannabinoid Plasma Exposure: A Preliminary Study.. Journal of xenobiotics, 15(3). https://doi.org/10.3390/jox15030066

MLA

Manca, Alessandra, et al. "COMT Genetic Variants and BDNF Level Associations with Cannabinoid Plasma Exposure: A Preliminary Study.." Journal of xenobiotics, 2025. https://doi.org/10.3390/jox15030066

RethinkTHC

RethinkTHC Research Database. "COMT Genetic Variants and BDNF Level Associations with Canna..." RTHC-07037. Retrieved from https://rethinkthc.com/research/manca-2025-comt-genetic-variants-and

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.