Twin Research, 2003; 6: 490-496
Genetic and environmental analysis of behavioral risk factors for adolescent
drug use in a community twin sample.
Siewert, E.A., Stallings, M.C., and Hewitt,
Adolescents with behavioral problems run a
higher risk of developing substance use problems than adolescents without
behavioral problems. In this study researchers investigated self reported
behavioral problems in twins. Two groups of behavior were analyzed: externalizing
behaviors (conduct problems, hyperactivity and school problems) and internalizing
behaviors (low self-esteem, neuroticism, and social withdrawal). Using several
models to interpret the data, researchers found evidence that externalizing
and internalizing behavior are both heritable and genetically distinct from
one another. These findings suggest that two separate genetic pathways lead
to externalizing or internalizing behavioral problems. The type of behavioral
problem may then influence the risk factors and motivations for substance
use, abuse and dependence.