With the opioid crisis continually increasing, it is crucial to understand the biological and biochemical mechanisms of opioid abuse. This study aims to identify the genetic risk variants for opioid use disorder (OUD), along with determining genetic correlations and casual association with OUD and other traits.
This genome-wide association study included a total of 8,529 affected individuals with OUD, along with 71,200 opioid-exposed controls of European-American ancestry and 4,032 affected individuals, and 26,029 opioid-exposed controls of African-American ancestry. The primary outcomes of the study were the incidence of OUD as identified by various disease classifications and DSM-IV-defined opioid dependence.
The findings suggested that a functional coding variant in OPRM1, the primary target for opioids, reached genome-wide significance in European American Individuals. The findings were replicated in two samples, with single-nucleotide polymorphism-based heritability of OUD being 11.3%. The results further indicated that OUD was associated with 83 traits, including psychiatric illnesses, cognitive performance, and multiple substance use. Besides, OUD was also associated with depression, tobacco smoking, neuroticism, and cognitive performance.
The research concluded that there was a significant association of opioid use disorder with the OPRM1 variant. However, the statistically significant data was limited to individuals with European ancestry only.