Peripheral Expression of Dopamine Genes as a Biomarker for Cocaine Addiction in Humans.

UNLABELLED: <p>

Introduction

Objective measures for the severity of addiction are needed to identify and appropriately stratify patients into effective treatment groups for intervention and recovery. Our aim was to determine if blood-derived, dopamine-related biomarkers hold predictive validity in patients with cocaine use disorder (CUD).

METHODS

A total of 349 participants (163 patients with moderate-to-severe CUD and 186 healthy control participants without a history of substance use disorder) were recruited for a cross-sectional case-control study in the East of England, UK. Data on individual differences in CUD-related traits, e.g., impulsivity, sensation-seeking, were collected. Measurements included mRNA transcription of dopamine-related genes (DRD2, DRD3, DRD4, and COMT) and risk alleles (rs6277, rs1800497, rs12364283, rs6280, and rs4680).

RESULTS

CUD patients showed elevated DRD2 mRNA in peripheral blood (B0 = 0.43, 95% CI [0.13, 0.73], pFDR = 0.020) and the DRD2-related rs6277 risk allele was associated with CUD diagnosis (odds ratio = 2.16, 95% CI [1.15, 4.17], p = 0.02). DRD2 mRNA levels related to self-reported impulsivity (B0 = -0.17, 95% CI [-0.32, -0.03], p = 0.013).

CONCLUSIONS

Blood-based expression of DRD2 may be a useful biomarker related to CUD diagnosis and related traits. </p>.