Abstract
Addictive disorders are complex diseases influenced by both genetic and
environmental factors. Heritability of these disorders is moderate to high. Genes that
increase the risk of addiction to a substance actually increase the risk of addiction to
other substances. This means it is mainly through broad externalizing pathways that
genes increase the risk of addiction. The current level of our knowledge in genetics is
less than enough to have clinical applications. Probably, in the near future, we will be
able to provide our patients with individualized report about their susceptibility to
addiction.