Specificity of Genetic and Environmental Risk Factors for Use and Abuse Dependence of Cannabis, Cocaine, Hallucinogens, Sedatives, Stimulants, and Opiates in Male Twins

• Published in: The American journal of psychiatry 2003-04, Vol.160 (4), p.687-695
• Main Authors: Kendler, Kenneth S., Jacobson, Kristen C., Prescott, Carol A., Neale, Michael C.
• Format: Article
• Language: English
• Subjects: Addictive behaviors; Adult; Adult and adolescent clinical studies; Biological and medical sciences; Cocaine-Related Disorders - epidemiology; Cocaine-Related Disorders - genetics; Comorbidity; Diseases in Twins - epidemiology; Diseases in Twins - etiology; Diseases in Twins - genetics; Drug abuse; Drug addiction; Drug dependency; Environmental aspects; Genetic factors; Genetic Predisposition to Disease - epidemiology; Genetic Predisposition to Disease - genetics; Genetics; Humans; Male; Males; Marijuana Abuse - epidemiology; Marijuana Abuse - genetics; Medical sciences; Men; Middle Aged; Multivariate Analysis; Opioid-Related Disorders - epidemiology; Opioid-Related Disorders - genetics; Phenotype; Prevalence; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Registries; Risk assessment; Risk Factors; Sex Factors; Substance-Related Disorders - epidemiology; Substance-Related Disorders - etiology; Substance-Related Disorders - genetics; Twin studies; Twins; Twins, Dizygotic - genetics; Twins, Monozygotic - genetics; Virginia - epidemiology
• ISSN: 0002-953X; 1535-7228
• DOI: 10.1176/appi.ajp.160.4.687

OBJECTIVE: Data on use and misuse of six classes of illicit substances by male twin pairs were used to examine whether genetic and shared environmental risk factors for substance use disorders are substance-specific or -nonspecific in their effect. METHOD: Lifetime history of use and abuse dependence of cannabis, cocaine, hallucinogens, sedatives, stimulants, and opiates was assessed at personal interview in both members of 1,196 male-male twin pairs ascertained by the Virginia Twin Registry. Multivariate twin modeling of substance-nonspecific (common) and substance-specific genetic, shared environmental, and unique environmental risk factors was performed by using the program Mx. RESULTS: High levels of comorbidity involving the different substance categories were observed for both use and abuse dependence. One common genetic factor was found to have a strong influence on risk for illicit use and abuse dependence for all six substance classes. A modest influence of substance-specific genetic factors was seen for use but not for abuse dependence. Shared environmental factors were more important for use than for abuse dependence and were mediated entirely through a single common factor. CONCLUSIONS: In an adult population-based sample of male twins, both the genetic and the shared environmental effects on risk for the use and misuse of six classes of illicit substances were largely or entirely nonspecific in their effect. Environmental experiences unique to the person largely determine whether predisposed individuals will use or misuse one class of psychoactive substances rather than another.