Genetic and environmental variation in the initiation of adolescent drug use


Medland, Sarah; E; Neale, Michael; & C (2008). Genetic and environmental variation in the initiation of adolescent drug use. 2008 Add Health Users Conference. Bethesda, MD.


Genetic influences have been found to influence the progression from drug initiation to abuse and dependence for a range of substances. However, relatively little is known about the initiation of poly substance use. The aim of the present analyses was to examine the magnitude and structure of genetic and environmental influences underlying the covariation in the initiation of multiple substances. To this end we analyzed the Wave III initiation variables (for tobacco, alcohol, marijuana, cocaine and prescription drugs) from the genetically informative samples (twins, full siblings and half siblings) using variance components analyses within a behavioral genetic framework. This type of analysis allows us to address questions such as to what extent can a common genetic influence explain the covariation between initiation of tobacco, alcohol, marijuana and cocaine. Results support the hypothesis that variation in the initiation of substance use across drugs is due to genetic and environmental influences that affect multiple drug types rather than substance specific factors. Strategies for extending these analyses to include data from friends and predictors such as sensation seeking and drug availability are discussed.


Reference Type

Conference proceeding

Book Title

2008 Add Health Users Conference


Medland, Sarah
Neale, Michael

Year Published


City of Publication

Bethesda, MD

Reference ID