Cody J. Connor, BS

While many cultures strongly endorse the cosmetic effect of tan skin, the dangers of attaining it often evade the minds of those who seek that “beautiful” status. In fact, for many of those that do consider these dangers, the remote consequences do not seem to outweigh the immediate benefits. Thus, the perfect storm for addiction is born.

The toxic consequences of excessive UV exposure are well-established, ranging from acute effects like cutaneous burns (erythema), tanning, and local immunosuppression, to more long-term consequences like photoaging , immunosuppression, and photocarcinogenesis [1].By inducing DNA damage, chronic UV exposure leads to accumulated genetic changes that, in conjunction with the immunosuppressive effects, increase the incidence of skin cancers like basal cell carcinoma, squamous cell carcinoma, and melanoma [1]. Though tanning is conceptualized as a benefit of UV exposure, the underlying mechanism is one of skin damage, and the increased melanin production serves as a self-defense mechanism signifying the degree of insult. As many dermatologists will say, there is no such thing as a safe or healthy tan, though this point is often a difficult one to make to patients.

Indoor tanning has become a booming business in recent years, and its increasing popularity parallels the increasing incidence of skin cancers like melanoma, particularly in the younger population [2]. Why is this practice continuing to grow despite the well-supported and widely-expressed consequences? In addition to the obvious social motivations for indoor tanning, some consider it practical, believing that attainment of a quick, baseline tan provides protection against damaging sunburns. On the contrary, the practice of indoor tanning to prevent burns has been shown to increase rates of melanoma above those of non-tanners, even in individuals who have never burned from indoor or outdoor UV exposure [3].

Beyond the frequently cited reasons for tanning indoors, there is evidence that internal forces are at work in many tanners: forces that are less conscious, less controllable, and potentially capable of transforming the behavior from a conscious decision to an uncontrollable, and harmful, addiction. Warthan et al. (2005) were the first to explore this concept of UV light (UVL) addiction through the use of two standard assessment tools conventionally used to evaluate for drug addiction, the DSM-IV-TR and the CAGE criteria [4]. They found that 26% of questioned beachgoers met the modified CAGE criteria and 53% met the DSM-IV-TR criteria for a UVL- related substance disorder. Similar results have been reproduced among indoor tanners, with 41% demonstrating “tanning addictive disorder” and 33% demonstrating problematic tanning behavior [5]. One study reported tanning addiction in 39% of college-age subjects and found that those individuals also reported increased use of alcohol, marijuana, and other drugs, possibly signifying underlying addictive tendencies [6]. Recently, a more specific assessment tool, called the Structured Interview for Tanning Abuse and Dependence (SITAD), proved valid in diagnosing tanning abuse (maladaptive tanning habits leading to social, interpersonal, health, or legal problems) and tanning dependence (characterized by loss of control, loss of time, loss of ability to cut down, physical and psychological problems, tolerance, and withdrawal) [7].

Indoor tanners cite feelings of relaxation and warmth as additional attractions to the act, and this poses the question of whether it is these factors, as opposed to the UVL, that provide the reinforcement necessary for generating addiction. One study sought to make this distinction with the use of a blinded, repeated-choice trial in which patients were allowed to choose between two tanning beds, one of which had the UVL filtered out. On repeat choice between the two beds, 95% of subjects unknowingly selected the UV bed over the non-UV bed, indicating that the UVL serves as the reinforcing stimulus [8]. But what is it about the body’s response to UVL that creates this reinforcing sensation?

In frequent tanners, exposure to UV radiation through indoor tanning has been demonstrated to increase cerebral blood flow to reward regions of the brain, including the anterior insula, the medial orbitofrontal cortex, and the dorsal striatum [9]. Associated with this effect, subjects also reported a subsequent decrease in desire to tan. Exposure to UV radiation also induces cutaneous production of endogenous opioids [10], suggesting that endorphins may play a role in the addictive nature of indoor tanning. In fact, this possibility has been explored in past studies, and though plasma endorphin levels were not found to fluctuate significantly with UV exposure [11], administration of the opioid receptor antagonist, naltrexone, has been shown to decrease the rewarding effects of UV exposure, eliminate the unconscious preference for UV versus non-UV tanning beds, and even, in some frequent tanners, induce physiologic withdrawal-like symptoms including nausea, difficulty concentrating, and jitteriness [12, 13].

Part of the addictive nature of indoor tanning, for some, may be attributed to an underlying psychological disorder like seasonal affective disorder (SAD), body dysmorphic disorder (BDD), impulse control disorder, obsessive-compulsive disorder, anorexia, or depression [14]. Frequent tanning has been associated with SAD, with one study finding that “frequent” indoor tanners were more likely to report symptoms of SAD than “regular” tanners and those that never tanned [15]. More than 80% of frequent tanners reported symptoms of SAD, and of all subjects with SAD symptoms, tanning frequency was nearly double those without symptoms. Other researchers observed a significant association between indoor tanning and body dysmorphic disorder (BDD) [16]. Of 200 subjects with diagnosed BDD, 25% reported BDD-related indoor tanning, with various motivations including to darken “pale” skin, to reduce the appearance of scars and lesions resulting from compulsive picking, to hide already-inconspicuous or absent acne and blemishes, to even out heterogeneous skin tone, and to distract from characteristics like skin wrinkles, balding, or dark body hair. In this study, 52% of reported tanners had received dermatologic treatment in the past, but only 7.6% reported that treatment diminished their preoccupation with the treated area, and only 5.1% said that their BDD improved as a result [16]. This exemplifies the notion that patients with BDD are historically difficult to treat, and it further reveals that tanning as a component of BDD self-treatment may be an extremely difficult habit to extinguish, especially if the provider recommending cessation is not aware of the underlying condition fueling the behavior.

Overall, it is important to recognize the increasing popularity of indoor tanning and the dramatic effect it is having on skin cancer incidence in America. With the social pressures of adolescence and the American focus on physical appearance, our youth, particularly, are being swept into the act with little thought to the consequences. What begins as an attempt to fit in or gain approval can quickly become a maladaptive obsession or an unwitting addiction, with physiologic underpinnings that parallel the more widely known concept of substance abuse. While the substance in question is not a drug like heroin or cocaine, UV light is still a dangerous exposure that, in excess, can lead to morbidity and mortality. Realizing the existence of indoor tanning addiction is the first step in solving this mounting issue, and further study is certainly indicated to better understand the physiologic mechanisms in play and to more effectively target and treat the addiction to eliminate this harmful behavior.

References

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