Now, a growing body of evidence suggests that, as with cigarettes, simply knowing the behavior is bad isn't going to stop people if the behavior is addictive. A new study, released Monday in the journal Archives of Dermatology, adds to that body of literature that connects regular visits to a tanning booth with addictive behavior.
The researchers say the study falls short of proving such a link beyond a shadow of a doubt. But for some, the idea that tanning is addictive makes sense.
"I absolutely believe that I was addicted to tanning," said 27-year-old melanoma survivor Kristi Setzer, who said she began a tanning regimen to look good for her wedding in 2006.
"I felt that I would look thinner and not blend in with my wedding dress," Setzer, now a law student, recalled.
After going tanning, she estimates, almost every day for a year before her wedding, she continued afterward, despite better than average knowledge of its possible effects.
"I knew that melanoma had serious consequences," Setzer said. "My uncle actually died after a battle with melanoma, but even though I knew that, I felt compelled to go tan.
"Even after my wedding I continued indoor tanning until August of 2008, when I received my diagnosis of melanoma," she said.
While physicians agree that tanning can have severe and negative effects, a number of things need to be known before it can be considered a true addiction.
"I think there's growing evidence that it can be addicting for a minority of individuals," said Catherine Mosher, a clinical psychologist and post-doctoral research fellow with Memorial Sloan Kettering Cancer Center's Department of Psychiatry and Behavioral Sciences and one of the study's authors. "Addiction is a very complex phenomenon, and it will take evidence from multiple sources to validate the idea that it is an addiction."
For the study, researchers asked 421 students about their tanning habits. Of these, 229 utilized indoor tanning beds. Among this group, between 30 percent and 40 percent, depending on the scale used, met the psychiatric diagnostic criteria for addiction. These "addicted" tanners also claimed more symptoms of anxiety as well as higher use of alcohol, marijuana and other substances.
"It's certainly an eye opener," Dr. James Spencer, a dermatologist in St. Petersburg, Fla., and a spokesman for the American Academy of Dermatology, said of the study. "We think that tanning gives a brief cosmetic change for a lifetime of problems with skin cancer and wrinkles."
But despite that, he said, dermatologists see people continue to tan -- a phenomenon that suggests the benefits are beyond cosmetic.
"People seem into it above and beyond that," Spencer said. "A significant percentage of the self-identified young people going to indoor tanning met the criteria for addiction.
"I think it's helpful for us to understand this behavior," in order to combat it, he said.
Tim Turnham, executive director of the Melanoma Research Foundation, said getting the answer to whether tanning is an addiction will be important in stopping people from getting cancer from it.
Understanding people's connection to the activity will help if there is something other than looks reinforcing the behavior, he said.
"It helps us craft our messages in a way I think will help us get through a little better," Turnham said.
While excessive tanning can prove destructive, and many frequent tanners know this and tan anyway, that alone does not make it addictive.
"It takes a long time to formally classify something as an addiction," said Suzette Glasner-Edwards, a clinical psychologist and researcher in UCLA's integrated substance abuse programs. "Typically it takes a lot of research studies to see if all the symptoms ... really conform to how we understand addiction to other things. It's a pattern of progressively losing control over a behavior. There are a lot of different ways we assess whether a person has lost control over drinking or drug use."
Glasner-Edwards explained that behavior would have to go beyond self-destructive and impair other areas of their life as well, such as social interaction and recreational activities.
"If they don't have impairment in their life as a result of it, then they won't get that diagnosis," she said.
Dr. Bryon Adinoff, chief of the division on addictions at UT Southwestern Medical Center, said that imaging studies may be necessary to link brain responses to tanning and establish it as an addiction.
"There's a suggestion that frequent tanners do display behaviors that are consistent with an addiction, but we'd like to have more information," he said. "There's always a danger of labeling any excessive, destructive behavior as an addiction."
Some possible mechanisms have been suggested.
One is that UV rays can help release endorphins in the human body, giving a natural "high."
But, "there's mixed evidence regarding this issue," said study author Mosher, reflecting the sentiments of a number of dermatologists.
Still, some say the seemingly addictive quality of tanning is hard to ignore.
"I think there's a very solid perception on the part of dermatologists ... that there's an addictive propensity for tanning," said Dr. David Fisher, chief of dermatology at Massachusetts General Hospital. He said that studies like this one help back that up with evidence so that, "We're not just saying, yes, it's our perception."
But it remains to see how those perceptions can be translated to frequent tanners.
Setzer was luckier than most with melanoma. The condition was caught early, and so after surgery she did not need further treatment.
Looking back, she recalls enjoying her tanning.
"It was a very relaxing experience. I felt very calm afterwards," she said, but she added: "That relaxation was really minimal compared with the stress of a cancer diagnosis."