The present study used a daily monitoring method that assessed the effects of GABRA2 variation on substance use as it occurred in the natural environment during emerging adulthood.
Polymorphisms across serotonergic (SLC6A4, 5-HTTLPR), dopaminergic (DRD4, u-VNTR), noradrenergic (SLC6A2, rs36021), and GABAergic (GABRA2, rs279858; GABRA6, rs3811995) genes were examined given prior support for associations with temperament, externalizing behavior, and substance use problems.
Consistent with earlier studies suggesting exposure is an important step in the development of substance use, we found the inclusion of substance exposure data in our analytic models markedly increased the strength of the genetic associations of GABRA2 haplotype with substance use.