A genetic risk factor that increases the likelihood that youth will engage in substance use can be neutralized by high levels of involved and supportive parenting, according to a new University of Georgia study.
The study, published in the February issue of the Journal of Consulting and Clinical Psychology , is the first to examine a group of youth over time to see how a genetic risk factor interacts with a child's environment to influence behavior.
"We found that involved and supportive parenting can completely override the effects of a genetic risk for substance abuse," says study co-author Gene Brody, Regents Professor in the UGA College of Family and Consumer Sciences. "It's a very encouraging finding that shows the power of parenting."
Brody and his colleagues, who include UGA Institute for Behavioral Research director Steven Beach and University of Iowa Associate Professor of Psychiatry Robert Philibert, focused their attention on a gene known as 5HTT that's involved in the transport of the brain chemical serotonin. Most people carry two copies of the long version of the gene, but those with one or two copies of the short version have been shown in several studies to have a greater likelihood of consuming alcohol and other substances and to have higher levels of impulsivity and risk taking.
The researchers interviewed 253 African-American families in rural Georgia over a four-year period. After obtaining informed consent from the parents and youth, they collected saliva samples for genetic testing.
The researchers found that nearly 60 percent of the youth had two copies of the long gene, while the remainder had one or two copies of the short gene that confers risk. As expected, the use of substances was low among 11 year-olds and increased as the youth aged. By age 14, 21 percent of the youth had smoked cigarettes, 42 percent had used alcohol, five percent had drank heavily and five percent had used marijuana.