Addiction to Indoor Tanning: Relation to Anxiety, Depression, and Substance Use

Objective  To assess the prevalence of addiction to indoor tanning among college students and its association with substance use and symptoms of anxiety and depression.

Design  Two written measures, the CAGE (Cut down, Annoyed, Guilty, Eye-opener) Questionnaire, used to screen for alcoholism, and the Diagnostic and Statistical Manual of Mental Disorders(Fourth Edition, Text Revision) (DSM-IV-TR) criteria for substance-related disorders, were modified to evaluate study participants for addiction to indoor tanning. Standardized self-report measures of anxiety, depression, and substance use also were administered.

Setting  A large university (approximately 18 000 students) in the northeastern United States.

Participants  A total of 421 college students were recruited from September through December 2006.

Main Outcome Measures  Self-reported addiction to indoor tanning, substance use, and symptoms of anxiety and depression.

Results  Among 229 study participants who had used indoor tanning facilities, 90 (39.3%) met DSM-IV-TR criteria and 70 (30.6%) met CAGE criteria for addiction to indoor tanning. Students who met DSM-IV-TR and CAGE criteria for addiction to indoor tanning reported greater symptoms of anxiety and greater use of alcohol, marijuana, and other substances than those who did not meet these criteria. Depressive symptoms did not significantly vary by indoor tanning addiction status.

Conclusion  Findings suggest that interventions to reduce skin cancer risk should address the addictive qualities of indoor tanning for a minority of individuals and the relationship of this behavior to other addictions and affective disturbance.

Extensive evidence has linked sunlamp or sun bed exposure to increased risk of melanoma and nonmelanoma skin cancers.^1-3 Despite ongoing efforts to educate the public about the health risks associated with natural and nonsolar UV radiation, recreational tanning continues to increase among young adults.⁴ In addition to the desire for appearance enhancement, motivations for tanning include relaxation, improved mood, and socialization.^5-7 These reinforcing properties of UV tanning have been conceptualized within an addiction framework.⁸ That is, repeated exposure to UV light may result in a behavior pattern similar to other types of substance-related disorder (SRD). In support of this hypothesis, a significant proportion (12%-53%) of young adults and beachgoers has met the criteria for having an SRD with respect to UV light tanning behavior.^7,9,10 In addition, having an SRD that involves tanning behavior and the use of indoor tanning devices has been positively associated with cigarette smoking among young adults.^9,11 However, to our knowledge, in-depth analyses of the reliability and validity of measures of SRDs that involve self-reported tanning behavior have not been conducted. Research also has not specifically focused on SRD with respect to indoor tanning and its relation to other psychopathological conditions. We hypothesized that a minority of college students would meet the criteria for an SRD with respect to indoor tanning and that having this disorder (determined by self-report) would be positively related to anxiety, depression, and substance use.

A total of 421 undergraduates were recruited from the psychology department research participant pool at a state university in the northeastern United States from September through December 2006. All study materials and procedures were approved by the university's institutional review board. After providing written informed consent, study participants anonymously completed questionnaires in groups ranging from 15 to 30 people. Participants reported their demographic information, whether they had ever tanned indoors, and frequency of indoor tanning during the past year.

To assess potential dependence on indoor tanning, we modified 2 measures that are widely used to identify SRDs: the 4-item CAGE (Cut down, Annoyed, Guilty, Eye-opener) questionnaire,¹² used for alcoholism screening, and the 7 diagnostic criteria for an SRD as outlined in the Diagnostic and Statistical Manual of Mental Disorders(Fourth Edition, Text Revision) (DSM-IV-TR).¹³ Versions of these measures were used in prior research to assess addiction to UV light tanning.^9,10 In this study, CAGE and DSM-IV-TR criteria referred to indoor tanning behaviors. Following the scoring procedures of Warthan and colleagues,¹⁰ 2 or more affirmative responses to items on the modified CAGE (mCAGE) and 3 or more affirmative responses to items on the modified DSM-IV-TR (mDSM-IV-TR) were, respectively, classified as indicating a probable SRD that involved indoor tanning. Scoring procedures for 3 questions in the mDSM-IV-TR with multiple parts were as follows: (1) question 1 was counted as affirmative only if both subparts were answered yes; (2) question 5 was counted as affirmative with 2 or 3 positive responses (any response other than none was classified as a positive response to subpart 5a); and (3) question 7 required a response of no to subpart 7c and a response of yes to subparts 7a and/or 7b to be considered an affirmative response. Internal consistencies for the mCAGE and mDSM-IV-TR were .58 and .56, respectively. Deletion of individual items did not significantly alter the α values, which are relatively low but consistent with those found in prior research on SRDs related to tanning behavior⁹ and most likely reflect the wide range of behaviors assessed by the measures and the brevity of those measures.

Participants completed the Beck Anxiety Inventory¹⁴ and the Beck Depression Inventory,¹⁵ which are widely used 21-item scales that assess symptoms of anxiety and depression, respectively, during the past week. Internal consistencies for the Beck Anxiety Inventory and the Beck Depression Inventory in the present study were .91 and .87, respectively. In addition, participants completed portions of the Core Alcohol and Drug Survey,¹⁶ a validated measure of substance use. Participants reported the number of days they had used 1 or more of 12 different substances (including tobacco, alcohol, and marijuana) during the past month. Response choices were 0, 1 through 2, 3 through 5, 6 through 9, 10 through 19, 20 through 29, and all 30 days.

Descriptive statistics were used to characterize the demographics of study participants, use of indoor tanning facilities, and indoor tanning addiction status. Addiction to indoor tanning was defined as meeting both mCAGE and mDSM-IV-TR criteria for addiction. Study participants with addictive tendencies met the criteria for addiction on either the mCAGE or mDSM-IV-TR. Study participants' frequency of indoor tanning during the past year and affirmative responses to items from the mCAGE and mDSM-IV-TR were computed to determine indoor tanning addiction status. Pearson χ² tests were used to examine associations among mCAGE, mDSM-IV-TR, and demographic factors (sex and skin type¹⁷). Logistic regression models were used to examine study participants' frequency of indoor tanning during the past year, symptoms of anxiety, symptoms of depression, and substance use as predictors of indoor tanning addiction status. Substance use variables included the use of tobacco, alcohol, and marijuana as well as the use of stimulants (ie, cocaine, amphetamines, and/or the nicotine in tobacco). Other substance categories were not analyzed owing to the small number (1-14) of participants who reported substance use; this small number would compromise the validity of the results.¹⁸ In addition, use of depressants (alcohol, marijuana, sedatives, and/or opiates) was not analyzed because only 5 participants with addictive tendencies or addiction to indoor tanning did not report use of these substances. Finally, Pearson χ² tests were used to examine relationships among anxiety, depression, the number of substances used during the past month (excluding alcohol), and lifetime use of indoor tanning devices and tanning addiction status. Alcohol use was excluded from these analyses because only 5 students with addictive tendencies or addiction to indoor tanning did not report alcohol use.

Demographic characteristics of the sample are given in Table 1. When asked whether they had ever tanned indoors, 237 of the 421 study participants (56.3%) answered affirmatively. Data from 8 of the 237 participants who had tanned indoors were omitted from subsequent analyses because of missing values on the mCAGE or mDSM-IV-TR measures. The mean (SD) number of visits to tanning salons during the past year among study participants with a lifetime history of indoor tanning was 23 (24). In addition, data from 70 of the remaining 229 study participants (30.6%) met mCAGE criteria and 90 (39.3%) met mDSM-IV-TR criteria for addiction to indoor tanning. The mCAGE and mDSM-IV-TR results were significantly correlated (κ = 0.43, P < .001; Table 2) and were not significantly associated with sex (P = .12) or skin type (P = .43).

Frequency of indoor tanning during the past year and affirmative responses to items from the mCAGE and mDSM-IV-TR by tanning addiction status are given in Table 3. Study participants who met criteria for addiction to indoor tanning reported more indoor tanning sessions during the past year than those with addictive tendencies (Table 4). In addition, both groups reported more indoor tanning sessions during the past year than those who did not meet the criteria for addiction to indoor tanning. Clinical categories of anxiety symptoms did not significantly vary as a function of lifetime use of indoor tanning history or tanning addiction status (P = .07; Table 5). However, as indicated in Table 4, study participants who met criteria for addiction to indoor tanning on both the mCAGE and mDSM-IV-TR reported greater symptoms of anxiety than those who did not. Symptoms of depression did not significantly vary by lifetime use of indoor tanning devices or tanning addiction status. When anxiety, depressive symptoms, and frequency of indoor tanning during the past year were included in the same logistic regression model, only frequency of indoor tanning significantly predicted tanning addiction status (addiction vs nonaddiction: Wald χ²=16.55, OR=1.03, P<.001).

Alcohol use during the past month was affirmed by 210 of 229 study participants (91.7%) who had tanned indoors, whereas 82 (35.8%) and 84 (36.7%) reported use of tobacco and marijuana, respectively, during the past month. Other substances (including cocaine, amphetamines, opiates, and steroids) were used by 1 to 14 students (range = 0.4% to 6.0%) during the past month. Although tobacco use and use of stimulants (cocaine, amphetamines, and/or the nicotine in tobacco) did not differ by tanning addiction status, students who met criteria for addictive tendencies or addiction to indoor tanning reported greater alcohol and marijuana use during the past month than those who did not (Table 4). In addition, the number of substances other than alcohol used during the past month varied by lifetime use of indoor tanning devices and tanning addiction status (Table 5). The highest rate of substance use was found among those who met criteria for addiction to indoor tanning, with 21 of 50 study participants (42.0%) affirming use of 2 or more substances during the past month. Only 29 of 181 study participants who had never tanned indoors (16.0%) and 20 of 119 study participants who tanned indoors and who were not addicted to this behavior (16.8%) affirmed this degree of substance use.

This study provides further support for the notion that tanning may be conceptualized as an addictive behavior for a subgroup of individuals who tan indoors⁸; it extends prior work by relating indoor tanning addiction to substance use and affective disturbance. Among the 229 study participants who had tanned indoors, 70 (30.6%) met mCAGE criteria and 90 (39.3%) met mDSM-IV-TR criteria for addiction to indoor tanning. Similarly, Poorsattar and Hornung⁷ found that 28% of undergraduates who had tanned indoors met mCAGE criteria for addiction to tanning. In this study, greater use of indoor tanning devices was associated with greater likelihood of addiction to this behavior, which supports the construct validity of the measures. The lack of association between skin type and addiction to indoor tanning may be attributable to the underrepresentation of darker skin tones. In addition, sex was not associated with addiction to indoor tanning, as in prior research on SRDs that involve UV-light tanning.^9,10 Women were overrepresented in this study and previous research^9,10; thus, further studies with sex-balanced samples are needed.

An interesting pattern of findings emerged with regard to the relations between substance use and SRDs that involve indoor tanning. Of the 50 study participants who tanned indoors and had positive mDSM-IV-TR and mCAGE responses, 42.0% reported use of 2 or more substances (excluding alcohol) during the past month, whereas 20 (16.8%) of those who tanned indoors and had negative mDSM-IV-TR and mCAGE responses and 29 (16.0%) of those who had never tanned indoors reported this degree of substance use. Furthermore, study participants who met the criteria for addiction to indoor tanning on either the mDSM-IV-TR or mCAGE reported greater use of alcohol and marijuana, compared with those who did not meet these criteria. Other studies^11,18-20 have found positive associations between substance use and indoor tanning among adolescents and young adults. In this study, tobacco use and the use of stimulants (cocaine, amphetamines, and/or the nicotine in tobacco) did not differ by tanning addiction status, whereas another study⁹ found a positive association between cigarette smoking and addiction to tanning. Overall, findings suggest that individuals who use drugs may be more likely to develop dependence on indoor tanning because of a similar addictive process. In addition, tanning and drug use may be reinforced by peer group norms.

Anxiety and depression are often comorbid with substance dependence,²¹ and the present findings suggest that affective disturbance may also be comorbid with dependence on indoor tanning. Specifically, study participants who tanned indoors and had positive mDSM-IV-TR and mCAGE responses had approximately twice the rate of moderate-to-severe anxiety and depressive symptoms than study participants who tanned indoors and had negative responses on both measures and those who had never tanned indoors. Similarly, prior research found a positive association between seasonal affective disorder and indoor tanning frequency.²² In this study, however, anxiety symptoms predicted group classification (ie, affirmative vs negative mDSM-IV-TR and mCAGE responses), whereas depressive symptoms did not predict this classification. In addition, study participants with addictive tendencies (either affirmative mDSM-IV-TR or mCAGE responses) had levels of anxiety and depressive symptoms that did not significantly differ from those who were not addicted to indoor tanning.

If associations between affective factors and indoor tanning behavior are replicated, results suggest that treating an underlying mood disorder may be a necessary step in reducing skin cancer risk among those who frequently tan indoors. Researchers have hypothesized that those who tan regularly year round may require more intensive intervention efforts, such as motivational interviewing, relative to those who tan periodically in response to mood changes or special events.^23,24 Further research should evaluate the usefulness of incorporating a brief anxiety and depression screening for individuals who tan indoors. Patients with anxiety or depression could be referred to mental health professionals for diagnosis and treatment.

Limitations of this study include its cross-sectional design and reliance on self-report measures. In addition, the sample consisted of undergraduate students in the northeastern United States; thus, results may not be generalizable across individuals of different age groups, socioeconomic levels, and geographic regions. Although results supported the convergent validity of our new self-report measures of addiction to indoor tanning, the α values were relatively low. These values tend to underestimate reliability, especially when measures contain fewer than 10 items.²⁵ Further reliability testing and in-depth analyses of the measures, such as cognitive interviewing, should be conducted in future studies to strengthen their validity for use with those who tan. For example, use of cognitive interviewing would allow researchers to ascertain whether affirmative responses to item 1a (Table 3) indicate a preoccupation with tanning or agreement with the notion that more time spent tanning darkens the skin. Research is needed to further validate the self-report measures of addiction to indoor tanning by including objective measures of UV radiation exposure (eg, spectrophotometry). It also would be interesting to explore the physiologic and psychological mechanisms underlying the relations among addiction to indoor tanning, other addictive behaviors, and affective disturbance. Such research would inform biopsychosocial conceptualizations of tanning behavior and tailored interventions that address individuals' motivations for tanning and the relation of those motivations to psychopathological conditions.

Correspondence: Catherine E. Mosher, PhD, Department of Psychiatry and Behavioral Sciences, Memorial Sloan-Kettering Cancer Center, 641 Lexington Ave, Seventh Floor, New York, NY 10022 (mosherc@mskcc.org).

Accepted for Publication: November 6, 2009.

Author Contributions: Both authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Mosher and Danoff-Burg. Analysis and interpretation of data: Mosher. Drafting of the manuscript: Mosher. Critical revision of the manuscript for important intellectual content: Mosher and Danoff-Burg. Statistical analysis: Mosher. Obtained funding: Mosher. Administrative, technical, and material support: Mosher and Danoff-Burg. Study supervision: Mosher and Danoff-Burg.

Financial Disclosure: None reported.

Funding/Support: The work of Dr Mosher was supported by grant F32CA130600 from the National Cancer Institute.

Role of the Sponsor: The sponsor had no role in the design and conduct of the study; in the collection, analysis, and interpretation of data; or in the preparation, review, or approval of the manuscript.

Previous Presentation: This study was presented in part at the Society of Behavioral Medicine Annual meeting; April 23, 2009; Montreal, Quebec, Canada.