The COMT rs4680 Met Allele Is Associated with High Impulsivity, Hyperactivity and Inattention in Patients with Opioid Use Disorder

Background: Previous research has linked opioid use disorder (OUD) to neuronal reward systems and impulsivity. The aim of this study was to examine the influence of COMT rs4680 Val158Met polymorphism on impulsivity, hyperactivity and inattention (IHI) in patients with OUD. Methods: Open-label, cross-sectional cohort study was conducted involving individuals, 18 to 65 years, with OUD who either were included in opioid agonist treatment (OAT)—or same group of individuals who were awaiting induction on extended-release naltrexone (XR-NTX). Adult ADHD Self-Report Scale 18-item version was used to score IHI, and saliva samples were collected for genotyping (TaqMan assays). Logistic regression models were used to analyze the data. Results: The data of the entire cohort (n = 206) showed that carriers of one or two Val alleles had a negative association with IHI compared to Met/Met carriers (Val/Met OR = 0.43, p-value = 0.017, and Val/Val OR = 0.29, p-value = 0.005). Individuals included in OAT not waiting for XR-NTX (n = 120) exhibited the same pattern as observed in the entire cohort (Val/Met OR = 0.33, p-value = 0.019, and Val/Val OR = 0.18, p-value = 0.004), but not those who chose XR-NTX (Val/Met OR = 0.60, p-value = 0.353, and Val/Val OR = 0.47, p-value = 2.779). Conclusions: The present study revealed that individuals with OUD carrying the COMT rs4680 Val allele had lower IHI scores than Met/Met carriers. Hence, in individuals with OUD, the COMT rs4680 Met allele is associated with higher IHI symptom burden.