Genetic and environmental influences on symptoms of adult antisocial
behavior (AAB) and alcohol dependence at ages 17, 20, and 24 were
examined cross-sectionally and longitudinally in 188 monozygotic and
101 dizygotic male twin pairs. A moderate genetic influence on both AAB
and alcohol dependence was found at each age, with a substantial
proportion of this influence common to the two disorders, suggesting
they share susceptibility genes. Biometrical models showed that
continuity effects accounted for most of the stable variance in
symptoms of both AAB and alcohol dependence, indicating that genetic
and environmental effects associated with each of these disorders were
similar at each age. Significant cross-lag effects (effects of alcohol
dependence contributing to variance in AAB and vice versa) were
observed at ages 20 and 24 for both disorders. The largest and
theoretically most interesting of these effects indicated that one
sixth of the genetic influence on AAB at age 20 was due to genetic
effects associated with alcohol dependence at age 17. Thus, alcohol
dependence symptoms at age 17 in particular had an effect on antisocial
behavior symptoms at age 20, suggesting that alcohol involvement in
adolescence may ensnare otherwise desisting youth in persistent
antisocial behavior.The present study
was supported in part by grants from the National Institute of Drug
Abuse (DA 05147) and the National Institute on Alcohol Abuse and
Alcoholism (AA09367). We are grateful to a number of individuals for
their assistance in coding and entering data that were not previously
available. Our special thanks are due to Irene Elkins, Linda Springer,
Kari Melchert, and Kristen Abernethy for their gracious and timely
help.