Specificity in genetic and environmental risk for prescription opioid misuse and heroin use

• Published in: Psychological medicine Vol. 53; no. 14; pp. 6828 - 6837
• Main Authors: Dash, Genevieve F., Gizer, Ian R., Martin, Nicholas G., Slutske, Wendy S.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.10.2023
• Subjects: Addictive behaviors; Behavior; Biometrics; Cannabis; Cocaine; Crack cocaine; Drug abuse; Drug use; Environmental aspects; Environmental factors; Gender differences; Genetic diversity; Genotype & phenotype; Hallucinogens; Heroin; Influence; Inhalants; Liability; Marijuana; Narcotics; Opioids; Original; Original Article; Phenotypes; Phenotypic variations; Prescription drugs; Psychological distress; Risk factors; Sedative drugs; Sedatives; Solvents; Stimulants; Twin studies; Twins; multivariate; prescription opioids; heroin; twin study; Drug use
• ISSN: 0033-2917; 1469-8978
• DOI: 10.1017/S003329172300034X

Many studies aggregate prescription opioid misuse (POM) and heroin use into a single phenotype, but emerging evidence suggests that their genetic and environmental influences may be partially distinct. In total, 7164 individual twins (84.12% complete pairs; 59.81% female; mean age = 30.58 years) from the Australian Twin Registry reported their lifetime misuse of prescription opioids, stimulants, and sedatives, and lifetime use of heroin, cannabis, cocaine/crack, illicit stimulants, hallucinogens, inhalants, solvents, and dissociatives via telephone interview. Independent pathway models (IPMs) and common pathway models (CPMs) partitioned the variance of drug use phenotypes into general and drug-specific genetic ( ), common environmental ( ), and unique environmental factors ( ). An IPM with one general and one general factor and a one-factor CPM provided comparable fit to the data. General factors accounted for 55% ( = 14%, = 41%) and 79% ( = 64%, = 15%) of the respective variation in POM and heroin use in the IPM, and 25% ( = 12%, = 8%, 5%) and 80% ( = 38%, = 27%, 15%) of the respective variation in POM and heroin use in the CPM. Across both models, POM emerged with substantial drug-specific genetic influence (26-39% of total phenotypic variance; 69-74% of genetic variance); heroin use did not (0% of total phenotypic variance; 0% of genetic variance in both models). Prescription sedative misuse also demonstrated significant drug-specific genetic variance. Genetic variation in POM, but not heroin use, is predominantly drug-specific. Misuse of prescription medications that reduce experiences of subjective distress may be partially influenced by sources of genetic variation separate from illicit drug use.