As many as a third of young people who use indoor tanning facilities may be addicted to the behavior, researchers reported Monday. The findings are the latest to suggest that tanning, whether natural or indoors, activates the same parts of the brain triggered by drug dependence.
The study screened college students using two standard questionnaires designed to assess addiction and modified to assess tanning behavior. Among 229 people who said they had used indoor tanning facilities in the past, 39% met one measure's criteria for addiction; 30% met the other measure's criteria.
The tanners were aware that repeated exposure to ultraviolet light, either indoors or outside, increases the risk of several types of skin cancer, including the most dangerous type, melanoma, said the study's lead author, Catherine E. Mosher, a post-doctoral research fellow in psychiatry and behavioral science at Memorial Sloan-Kettering Cancer Center in New York.
"They know it's bad for them," Mosher said. "This is not about appearance. It's for relaxation, to improve mood or to socialize."
The study, released Monday in the Archives of Dermatology, also found that people who met the criteria for addiction had more symptoms of anxiety and had much higher rates of substance use than those in the study who didn't tan excessively. Among people who never tanned indoors or were not seemingly addicted to the behavior, 17% said they had used two or more addictive substances (such as tobacco, marijuana or stimulants but excluding alcohol) in the previous month, compared with 42% of those who scored positive for addiction on both of the diagnostic measures.
"There might be a similar mechanism underlying substance-use behavior and tanning behavior," Mosher said. "Both may be ways of coping with emotions. There may be similar processes in the brain involved that need to be uncovered."
People who met the criteria for addiction had an average of 40 visits to a tanning salon in the past year, but some people made as many as 100 visits. More women than men participated in the study, but gender did not appear to be a factor in results.
In the first measure, from the Diagnostic and Statistical Manual of Mental Disorders-IV, addiction was defined as three or more positive answers to seven questions. On the other questionnaire – called CAGE, for Cut Down, Annoyed, Guilty, Eye-Opener – addiction was based on two or more positive responses to four questions.
While addiction to tanning may seem far-fetched, the participants' responses showed the behavior had disrupted their lives.
Among those who scored positive for addiction, 78% said they had tried to cut down on the time spent tanning but couldn't, and 78% said they felt guilty about using tanning beds or booths too much.
Further, 26% said that, when they wake up in the morning, they want to use a tanning bed or booth, and nearly 1 in 4 admitted that they had missed scheduled activities — social, occupational or recreational — because they decided to go to a tanning facility.
Evidence that tanning is addictive could explain why people ignore well-known health admonitions to avoid excess UV light, said Dr. Richard Wagner Jr., a dermatology professor at the University of Texas Medical Branch at Galveston and the lead author of a 2005 study published in the Archives of Dermatology that found similar rates of tanning addiction among beachgoers.
"A lot of times, these people don't really want to hear that tanning may be a problem," he said. "I hear this a lot from my skin-cancer patients. They are sort of in denial."
It's unclear how or why tanning can become compulsive, although exposure to UV light triggers production of brain chemicals called endorphins that boost mood. One study, published in 2006 in the Journal of the American Academy of Dermatology, found that frequent tanners experience some withdrawal symptoms when given naltrexone, a drug that blocks endorphins.
"Tanning makes them feel relaxed and calm," said Dr. Steven R. Feldman, a professor of dermatology, pathology and public health sciences at Wake Forest University in Winston-Salem, N.C., and the senior author of the 2006 study. "People think it's just the warmth that feels good. But there is something that UV light does to people that gives them a sense of relaxation. It's like a small narcotic hit."
Mental health professionals should ask about tanning when screening for other addictions, Mosher suggested. Moreover, people who have mood disorders and tan excessively may need specific therapy that addresses both issues, such as using antidepressants or cognitive therapy.
"The way they cope with a mood disorder may be to tan excessively," she said.