Dopamine-related genes and symptoms of depression may affect indoor tanning “addiction” among young women, a cross-sectional study found.
Two DRD2 dopamine receptor gene variants — the single nucleotide polymorphisms (SNPs) rs4648318 and rs4436578 — each roughly doubled the odds of indoor tanning addiction after adjusting for depressive symptoms, appearance beliefs, and tanning frequency.
When these variant genotypes coincided with depressive symptoms, the risk was 13-fold elevated for the SNP rs4648318 and over 10-fold increased for the SNP rs4436578, reported Darren Mays, PhD, MPH, of the Lombardi Comprehensive Cancer Center in Washington, D.C., and colleagues in Annals of Behavioral Medicine.
Understanding the associations in this study “may present an opportunity to counsel the patient or do some screening for combinations of risk factors like depression, like tanning, and essentially other behaviors that might go along with depression,” Mays told MedPage Today.
The findings also suggest that pharmacotherapy and counseling for depression may be effective interventions for limiting indoor tanning “in the presence of this constellation of risk factors,” the authors wrote, although acknowledging this data is preliminary and prospective studies assessing temporality of these relationships is needed.
This investigation aligns with prior neuroimaging studies that have shown heightened levels of dopamine after tanning and helps in understanding how tanning becomes an addictive behavior, noted Mays.
“This paper adds to the literature by providing some glimpse of what could be some biological basis for understanding more about genetic risk factors,” he said.
Clinicians have known that dopamine blockade causes some degree of withdrawal from tanning use, noted Amir Afkhami, MD, PhD, of the George Washington University School of Medicine in Washington D.C., who was not involved in the study.
“If more robust work is done in this area, if we do have convincing genetic markers, then, that can help better detect this disorder and help us formulate a better clinical characterization of the disorder that we currently lack in the most recent DSM [Diagnostic and Statistical Manual of Mental Disorders],” Afkhami told MedPage Today.
The researchers evaluated 292 women from the ages of 18 to 30 years in the Washington D.C. area. All participants were non-Hispanic white and had reported having an indoor tan within the last 12 months.
Participants self-reported information on clinical, demographic, and behavioral characteristics through an online questionnaire. The researchers used saliva samples for DNA in order to assess 34 SNPs in five genes that affect pathways that reward addictive behavior.
Tanning addiction was assessed via two screening questionnaires adapted from tests for other, more generally recognized addictive behaviors. Questions were along the lines of “have you tried unsuccessfully to cut down” and “do you give up other important activities to engage in the behavior.” Individuals endorsing at least two of four items on one of the questionnaires and at least three of eight items on the other were considered to be addicted. Reliability of this measure, in terms of Cronbach’s α, was 0.69 in the study sample, Mays and colleagues wrote.
Limitations of the study included the use of self-reported information and the narrow age range and racial-ethnic background of the cohort in a single geographic area. Also, although the authors offered a range of evidence to support the existence of tanning addiction, there are no formal, widely accepted diagnostic criteria.
More research is underway to build upon these findings, Mays noted. “What we are doing is using interventions that have been tested for cigarette smoking cessation as a model to develop an intervention for young women who may be addicted to indoor tanning as a way to help them quit.”
The study was funded by the the National Institutes of Health and the Harry J. Lloyd Charitable Trust.
Mays and Afkhami reported no disclosures.
Source: MedicalNewsToday.com
