You’re probably aware that tanning contributes to skin aging and the development of skin cancers, as well as damage to the eyes and immune system. But now there’s more bad news: it may be addictive, too.

Ultraviolet (UV) radiation, in the form of ultraviolet A (UVA) and B (UVB) light from the sun and tanning booths, causes skin cell damage; it is this damage that initiates the tanning process. And UV radiation is a proven human carcinogen, causing about 90 percent of the more than one million skin cancers diagnosed every year in the U.S.

Tanorexia and the Chemical Connection

The notion of UV tanning as addictive (the condition is sometimes termed “tanorexia”) is not new — previous studies and articles have demonstrated that some tanners display signs of behavioral dependence. But recent evidence points to a physical addiction as well. In one 2007 study, investigators surveyed more than 350 students at the University of Washington in Seattle. In addition to collecting demographic information, researchers employed a modified version of the CAGE questionnaire, which helps identify addictive behavior by asking respondents about substance use and attitudes.

CAGE stands for cut down, annoyed, guilty, and eye-opener; tanners were asked questions such as “Have you ever felt you ought to cut down on your tanning?” and “Have people ever annoyed you by criticizing your tanning?” A full 12 percent of people surveyed, including 22 percent of women and 8 percent of men, answered two or more of the four CAGE questions positively, indicating a UV light substance-related disorder (SRD). Those with symptoms of addiction tanned more frequently, too: Sixteen percent of those with a suspected SRD tanned 20 or more times per month, compared to just nine percent of the sample as a whole.

Some researchers suspect that tanning can be such a hard habit to break because UV radiation stimulates the body’s production of endorphins, chemicals that produce feelings of calm and well-being. In several studies, relaxation has been cited as a major motivation for tanning, and in a 2006 study of almost 1,300 adolescent indoor tanners, those who claimed tanning improved their mood were more likely to have difficulty quitting.

Finally, a small 2006 study showed that frequent tanners may literally go through withdrawal symptoms when the stimulus of UV tanning was removed, suggesting that they had a full-blown substance addiction. While these studies in and of themselves are not conclusive due to the small sample size, they do show that this is something that deserves close study.