Addiction to alcohol can begin at any age. In 2013 researchers led by Monica Luciana reported that the brains of adolescents who began drinking developed differently from those who didn’t. Compared to those who refrained, the cerebral cortices of those who began drinking showed greater thinning in some parts and blunted development of white matter in others.
Now Luciana, professor and chair of the University of Minnesota Department of Psychology, is part of the NIH-funded ABCD (Adolescent Brain Cognitive Development) consortium. ABCD is following 11,500 children for at least five years, starting at age 9 or 10, with a long-range goal of finding strategies for preventing and treating substance abuse.
Luciana and a departmental colleague—U Regents Professor William Iacono—head the “twin hub” of the study, examining 600 of the children.
“Two-thirds of our participants are fraternal or identical twins,” says Luciana.
Twins tell the tale
Twins are ideal subjects for studying the effects of genetics versus environmental factors that influence adolescents’ responses to alcohol and other drugs. For example, suppose identical twins, which share the same genes, both had propensities for thrill-seeking or risk-taking behavior.
“If these tendencies have effects on the brain, both twins’ brains will show those effects relative to others who are not risk-takers,” says Luciana. “However, if one twin should drink more than the other and if even moderate alcohol use is toxic to developing adolescent brains, the twin who drinks more will show alcohol-induced brain changes above and beyond what’s seen just from the risk-taking tendency.”
If either of these scenarios should occur, it would allow researchers to disentangle how these two important factors affect the brain: a genetic risk-taking tendency and the behavior of drinking alcohol.