Greater symptoms of depression combined with differences in a dopamine-related gene appear to play a role in compulsive use of tanning beds among young women, according to a new study published in the Annals of Behavioral Medicine. Dopamine is a neurotransmitter important to the brain’s pleasure and reward system.
Excess exposure to ultraviolet (UV) radiation can lead to melanoma and non-melanoma skin cancer. Most UV exposure is from the sun, but exposure from indoor tanning accounts for 10 percent of skin cancer cases in the U.S. There will be an estimated 96,480 new cases of melanoma in the United States and 7,230 deaths from the disease in 2019.
For the study, researchers at Georgetown Lombardi Comprehensive Cancer Center evaluated survey responses from 292 non-Hispanic white women in the Washington, D.C. area, ages 18 to 30, who used indoor tanning beds, sunlamps or sun booths.
The survey asked questions about values and behaviors that might predispose a person to compulsive tanning, as well as a series of questions to determine if they had symptoms of depression.
The researchers also analyzed the participants’ saliva samples to find 34 single nucleotide polymorphisms (SNPs) in five different genes. SNPs are changes in one of the base molecules on a strand of DNA.
The specific SNPs that the researchers analyzed were in genes known to be linked to addictive behavior. The researchers adjusted their analyses based on indoor tanning frequency, value of appearance and depressive symptoms.
“By demonstrating that genes in behavioral reward pathways are associated with tanning addiction, we are providing stronger evidence that tanning addiction is a cancer risk behavior in need of intervention,” said lead author Darren Mays, Ph.D., M.P.H., an associate professor of oncology and member of the Cancer Prevention and Control Program at Georgetown Lombardi.
“This finding adds to a growing body of evidence from animal studies and neuroimaging studies that have been done in humans.”
They found a more than two-fold increased risk of compulsive indoor tanning in women with modifications to one particular SNP (known as rs4436578), and a slightly less than two-fold greater risk of addiction in modifications to another SNP (rs4648318).
When looking at whether the SNPs interacted with depressive symptoms to increase the risk of indoor tanning-addiction, they found a more than 10-fold increase if there were modifications to the rs4436578 SNP and a more than 13-fold increase in the rs4648318 SNP.
Next, Mays will explore the effectiveness of text messaging as an intervention to help young women quit if they are compulsively tanning. The research is funded by the Prevent Cancer Foundation.
“This grant will enable us to test behavioral interventions in young women who are addicted to indoor tanning,” Mays says. “We have used text messaging to intervene in other behaviors and have found that the personalized conversation we can deliver through this medium can help people take steps to quit.”