Peripheral Expression of Dopamine Genes as a Biomarker for Cocaine Addiction in Humans
Stacey Kigar1,2, Tsen Vei Lim1, Lorinda Turner1,2
1Department of Psychiatry, University of Cambridge, Cambridge, UK.
European Addiction Research
|February 21, 2026
Summary
Blood biomarkers, specifically DRD2 mRNA, show promise for diagnosing cocaine use disorder (CUD) and assessing related traits like impulsivity. This finding could aid in patient stratification for effective addiction treatment.
Area of Science:
- Neuroscience
- Genetics
- Addiction Medicine
Background:
- Objective measures are crucial for diagnosing addiction severity and stratifying patients for treatment.
- Dopamine-related biomarkers in blood require investigation for their predictive validity in cocaine use disorder (CUD).
Purpose of the Study:
- To investigate if blood-derived dopamine-related biomarkers can predict cocaine use disorder (CUD) severity.
- To explore the association between genetic variations in dopamine pathways and CUD.
Main Methods:
- A cross-sectional case-control study involving 349 participants (163 with CUD, 186 controls).
- Collected data on CUD-related traits, including impulsivity and sensation-seeking.
- Measured mRNA transcription of dopamine genes (DRD2, DRD3, DRD4, COMT) and specific risk alleles.
Main Results:
- Elevated DRD2 mRNA levels were observed in the peripheral blood of CUD patients (p=0.020).
- The DRD2 rs6277 risk allele was significantly associated with CUD diagnosis (OR=2.16, p=0.02).
- DRD2 mRNA levels correlated with self-reported impulsivity (p=0.013).
Conclusions:
- Blood-based DRD2 gene expression may serve as a valuable biomarker for CUD diagnosis.
- DRD2 biomarkers are potentially linked to CUD diagnosis and associated behavioral traits.
- Further research into dopamine-related biomarkers could enhance addiction treatment strategies.
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