To provide insights into the biology of opioid dependence (OD) and opioid use (i.e., exposure, OE), we completed a genome-wide analysis comparing 4503 OD cases, 4173 opioid-exposed controls, and 32,500 opioid-unexposed controls, including participants of European and African descent (EUR and AFR, respectively). Among the variants identified, rs9291211 was associated with OE (exposed vs. unexposed controls; EUR z= −5.39, p= 7.2 × 10–8). This variant regulates the transcriptomic profiles of SLC30A9and BEND4in multiple brain tissues and was previously associated with depression, alcohol consumption, and neuroticism. A phenome-wide scan of rs9291211 in the UK Biobank (N> 360,000) found association of this variant with propensity to use dietary supplements (p= 1.68 × 10–8). With respect to the same OE phenotype in the gene-based analysis, we identified SDCCAG8(EUR + AFR z= 4.69, p= 10–6), which was previously associated with educational attainment, risk-taking behaviors, and schizophrenia. In addition, rs201123820 showed a genome-wide significant difference between OD cases and unexposed controls (AFR z= 5.55, p= 2.9 × 10–8) and a significant association with musculoskeletal disorders in the UK Biobank (p= 4.88 × 10–7). A polygenic risk score (PRS) based on a GWAS of risk-tolerance (n= 466,571) was positively associated with OD (OD vs. unexposed controls, p= 8.1 × 10–5; OD cases vs. exposed controls, p= 0.054) and OE (exposed vs. unexposed controls, p= 3.6 × 10–5). A PRS based on a GWAS of neuroticism (n= 390,278) was positively associated with OD (OD vs. unexposed controls, p= 3.2 × 10–5; OD vs. exposed controls, p= 0.002) but not with OE (p= 0.67). Our analyses highlight the difference between dependence and exposure and the importance of considering the definition of controls in studies of addiction.