Helium inhalation in adolescents: characteristics of users and prevalence of use.
Although systematic epidemiological studies of helium use have not been conducted, a Japanese case study discussing the death of a 14-year-old boy due to helium inhalation suggests that such inhalation may pose significant dangers to youth in some settings and is deserving of additional scientific investigation (Yoshitome et al. 2002). Numerous alarming videos of children, adolescents, and adults losing consciousness while inhaling helium can currently be accessed and viewed on the YouTube website (www.youtube.com) by using the search phrase "helium passing out."
Studies of volatile solvent users also suggest that helium inhalation can have serious health consequences. In the course of investigating North Carolina medical examiner reports for persons who died while inhaling volatile solvents such as gasoline or glue (Hall, Edwards & Howard 2010), the last author of this article (M.O. Howard) encountered reports of deaths due to helium inhalation that were judged accidental in nature and attributed to intentional (but possibly misguided) efforts on the part of the decedent to become intoxicated. That is, although helium is typically regarded as a nonpsychoactive gas (an issue we discuss below), these decedents were nonetheless attempting to get high using helium and suffocated in consequence. Ogden, Hamilton, and Whitcher (2010: 17) noted that "human exposure to a 100% helium environment will result in sudden loss of consciousness without warning and that "continued exposure will result in death from anoxia within a few minutes." The 17-year-old Riverside, CA decedent described above was found with a plastic bag over his head. This mode of inhalation (called "bagging") is typical of volatile solvent users who are trying to get high, but it is also possible the youth was trying to achieve some other effect or was attempting to commit suicide.
Helium is increasingly used to commit suicide. Howard and colleagues (2011) reviewed a total of 24 such cases, including ten helium-assisted suicides in North Carolina, which occurred most commonly in comparatively younger adults without terminal illness, a majority of whom suffered from substance use and other psychiatric disorders. Helium-assisted suicides appear to have recently increased in the U.K. (Ghodse et al. 2010), Canada (Ogden 2010), the U.S. (Howard et al. 2011), and Australia and Sweden (Austin et al. 2011), and possibly among youth (Howard et al. 2011) following publication of the suicide "how-to" book Final Exit (Humphrey 2002). Instructions on the use of helium to commit suicide are widely available on the Internet, CD-ROM, and VHS/DVD media (Howard et al. 2011).
Thus, associations of helium inhalation to substance abuse are complex and rarely researched. Some persons appear to use helium in an effort to become intoxicated and may thereby be at substantial risk for adverse health outcomes. A potentially significant percentage of the growing numbers of persons committing suicide via helium inhalation, which includes many adolescents, may suffer from substance use disorders (Howard et al. 2011). At present, it is unclear how prevalent helium inhalation is, particularly among high-risk adolescent populations who may be especially inclined to inhale helium in pursuit of intoxication experiences. Little is also known about the correlates and consequences of adolescent helium inhalation. This exploratory investigation examined the prevalence and correlates of helium inhalation in a large sample of atrisk youth. Specifically, we examined the prevalence of lifetime helium inhalation that was motivated by the intention to become intoxicated, determined the proportion of helium users who reported they actually had become intoxicated while inhaling helium, and assessed the sociodemo-graphic and clinical characteristics of adolescent helium users.
Participants were recruited from all Division of Youth Services (DYS) residential rehabilitation facilities in the state of Missouri to participate in a prior investigation of inhalant use among delinquent adolescents (i.e., Howard et al. 2008). The results reported in this study of helium users have never before been published. All residents of each facility were recruited at the time of data collection. Individual interviews required 30 to 90 minutes. Interviewing took place over a three-month period in 2004. Fifteen graduate students conducted study interviews. Interviewers completed a formal training protocol and were assisted by an on-site interview editor.
In total, 723 adolescents participated in the study. Each participant signed an informed assent form, which detailed information about the study and clarified that he or she was not required to participate and could discontinue the interview at any time. As the legal guardian of all youth receiving care, DYS provided formal consent for participation. The DYS IRB, Washington University Human Studies Committee IRB, and federal Office of Human Research Protections approved the informed consent and study protocols and the study was granted a Certificate of Confidentiality by the National Institute on Drug Abuse.
Demographic factors. Demographic factors including gender, race (i.e., White, Black, Latina/o, biracial, other race), and geographic location of family residence (i.e., urban, suburban, small town, rural) were recorded for each participant. For the logistic regression analyses reported below, race and geographic location variables were dummy-coded to identify participants as either White or non-White (i.e., Black, Latino, biracial, or other race) and living in either urban or nonurban (i.e., suburban, small town, or rural) locations. Additional self-report variables assessed whether youth had previously been diagnosed by a psychiatrist or other physician with a mental illness (yes or no) and had a personal history of auditory hallucinations (i.e., "hearing voices," yes or no).
Volatile Solvent Screening Inventory. All participants completed the Volatile Solvent Screening Inventory (VSSI), an interview developed by Howard and colleagues (2008) that assessed the lifetime and annual use of 55 volatile solvents and a variety of other inhalants. As part of this interview, participants were asked "Have you ever inhaled or 'huffed' helium through your nose or mouth in an effort to get high?" If participants responded affirmatively, they were asked "On how many days have you used helium in your lifetime?" and "On how many days did you use helium in the 12 months before you entered treatment?" If respondents reported any lifetime helium use, they were also asked whether or not "they actually did get high" when they inhaled helium.
Brief Symptom Inventory. The Brief Symptom Inventory (BSI) is a 53-item, self-report measure that assesses nine primary symptom dimensions that can be summed to reflect a global index of distress (Derogatis 1993). The nine BSI subscales assessed distress associated with somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism symptoms (Derogatis & Melisaratos 1983). For each item, respondents indicated to what extent they were "bothered or disturbed" by each listed symptom "over the past seven days including today." Responses were given on a five-point Likert-type scale ranging from 0 (not at all) to 4 (extremely). Overall current psychiatric distress was assessed with the Global Severity Index (GSI), which is the sum of responses to all 53 items. Higher GSI scores represent greater psychiatric distress. Prior studies have established the reliability and validity of the BSI, its subscales, and the GSI (Boulet & Boss 1991; Derogatis & Melisaratos 1983).
Psychopathic Personality Inventory. The Psychopathic Personality Inventory--Short Version (PPI-SV; Lilienfeld & Andrews 1996), a 56-item self-report measure, was used to assess empathy deficits and other personality dimensions associated with psychopathy. Participants responded to each item by using a Likert-type response scale indicating the degree to which each item is false or true "as applied to you" (1 = false, 2 = mostly false, 3 = mostly true, and 4 = true). The original 187-item Psychopathic Personality Inventory (PPI), from which the PPI-SV was derived, has shown good validity (Vaughn & Howard 2005). The original developers of the scale proposed that the PPI consists of eight subscales assessing: impulsive nonconformity, blame externalization, Machiavellian egocentricity, carefree nonplanfulness, stress immunity, social potency, fearlessness, and coldheartedness (Lilienfeld & Andrews 1996). Previous researchers have found adequate reliability for the PPI-SV total score ([alpha] = 0.76) (Vaughn & Delisi 2008).
Antisocial Process Screening Device. The Antisocial Process Screening Device (APSD) (Frick & Hare 2002), a 20-item measure, was used to assess psychopathic traits including callous/unemotionality, impulsivity, and narcissism. The APSD differs from the PPI-SV by directly assessing antisocial behaviors. Youth were asked to report how well each of 20 statements described them (0 = not at all true of them to 2 = definitely true of them). The internal consistency reliability of the full APSD (a = 0.76) was adequate in a previous study (Vitacco, Rogers & Neumann 2003).
Massachusetts Youth Screening Instrument. A modified Traumatic Experiences Scale of the Massachusetts Youth Screening Instrument--2nd Version (MAYSI-2; Grisso & Barnum 2000) was used to assess severity of past trauma. Participants completed four "yes or no" questions asking whether they had ever seen someone severely injured or killed in person (not in the movies or on TV), had a lot of bad thoughts or dreams about a bad or scary event that happened to you, had ever been badly hurt, or been in danger of getting badly hurt or killed, and had ever in their whole lives had something very bad or terrifying happen to them. Previous research has shown acceptable reliability of the scale ([alpha] = 0.73) (Grisso et al. 2001).
A modified six-item version of the Suicide Ideation Scale of the MAYSI-2 (Grisso & Barnum 2000) was used to assess feelings about ending one's life. Participants answered six "yes or no" questions asking whether they had ever wished they were dead, had ever given up hope for living, had felt like hurting themselves, had felt like killing themselves, had ever felt that life was not worth living, or had ever made an attempt to end their life. Previous research has shown acceptable reliability of the original scale ([alpha] = 0.83) in diverse youth populations (Grisso et al. 2001).
Self-Report of Delinquency Scale. Each participant completed the Self-Report of Delinquency Scale (SRD; Elliott, Huizinga, & Menard 1989). Participants were asked how often they engaged in each of 17 personal and property crimes in the year prior to entering treatment. Reponses could range from 0 = never to 8 = two to three times a day, with total possible scores ranging from 0 to 136. Previous research using the SRD has yielded good reliabilities ([alpha]'s = 0.82-0.85) (Howard et al. 2008; Munoz & Frick 2007).
Responses on the VSSI to the lifetime helium inhalation item were used to define two mutually exclusive groups: helium users (N = 81) and nonusers (N = 642). Bivariate comparisons of the two groups across demographic, psychosocial, and psychiatric characteristics were conducted using chi-square tests and Fisher's Exact Tests for categorical variables and t-tests for continuous variables, with degrees of freedom corrected for heterogeneity of variance as appropriate. Associations were also tested using multivariate logistic regression analysis. Significant relationships were summarized using effect size estimates (i.e., Cohen's D, Cramer's V).
On average, participants were approximately 15.5 years of age (SD = 1.2). Most participants were male (87.0%) and lived in urban (39.1%) or small town (39.6%) areas. Participants were racially diverse (Caucasian, 55.3%; African American, 32.9%; Latino/a, 3.9%; or Other, 7.8%). At the time of the survey, 40.3% of participants reported that their families had received public assistance. About half (i.e., 51.2%) of the sample had been diagnosed with a mental illness by a psychiatrist or other physician and a notable minority (14.7%) had experienced auditory hallucinations.
Approximately 11.5% (N = 81) of the total sample reported lifetime helium inhalation with the intention of becoming intoxicated. Most helium users (N = 73; 90.1%) reported lifetime use of an additional volatile solvent inhalant in an effort to get high. Approximately 34% (N = 27) of the 81 helium users reported they did get high when they inhaled helium. Approximately 40.0% (N = 32) of helium users reported less than five days of lifetime helium use, 24.7% (N = 20) of users reported lifetime helium use on five to ten days, 24.7% (N = 20) reported helium use on 11 to 99 days, and 11% (N = 9) reported use on 100 or more days. Roughly 60% (N = 49) of helium users had inhaled helium between one and ten times in the year prior to entering treatment.
Table 1 presents characteristics of the helium and nonhelium user subgroups. Significant differences were identified between helium users and nonusers with respect to race/ethnicity, geographic location of family residence, family receipt of welfare, lifetime diagnosis with a mental illness, and percentage initiating alcohol and marijuana use. Most helium users were White compared to only a slight majority of helium nonusers. Helium users were significantly more likely to live in small towns and rural areas, to have a previously diagnosed mental illness, and to initiate alcohol and marijuana use than helium nonusers.
Table 2 displays differences between helium users and nonusers with respect to psychiatric distress, suicidality, previous traumatic experiences, psychopathic traits, and antisocial attitudes and behaviors. Relative to helium nonusers, helium users reported significantly higher levels of total psychiatric distress and higher scores on the majority of the subscales of the BSI. Helium users also reported significantly more suicidality, traumatic experiences, antisocial traits and attitudes, and delinquent behaviors than nonusers.
Results of a multivariable logistic regression analysis of the entire sample (N = 723) assessing correlates of lifetime helium use are displayed in Table 3. Using findings from bivariate analyses to guide variable selection, eight covariates were entered simultaneously into the regression model: race/ethnicity (White vs. non-White), history of psychiatric diagnosis, suicidal ideation and traumatic experiences (MAYSI-2 subscales), psychiatric distress (i.e., GSI score), antisocial traits and attitudes (APSD total score and PPI total score), and total delinquent behavior score (i.e., SRD total score). Logistic regression revealed that Whites were more than five times more likely to report helium use than non-Whites. In addition, youth reporting higher levels of psychiatric distress, antisocial traits and attitudes (as indexed by the PPI), and delinquent behaviors were significantly more likely to report having engaged in helium use.
Lifetime helium use with the intention of becoming intoxicated was common in this at-risk youth sample, with more than one-in-nine adolescents reporting such use. Although we did not systematically assess youths' perceptions of risks associated with experimental or regular helium inhalation, the consensus of our interviewing team was that helium inhalation was generally perceived by users as harmless. It would be useful to know how prevalent helium inhalation is in the general youth population, how youth assess the risks posed by helium use, and which psychosocial and health consequences typically follow helium inhalation.
Another key issue for future research is whether helium inhalation produces psychoactive effects and, if so, what types of effects and by which neuropsychopharmacologic mechanisms. More than one third of helium users in the present sample reported having experiences of intoxication as a result of helium intoxication. Although these purported effects may be the result of placebo processes, it is possible that hypoxia associated with helium inhalation could produce dizziness, alterations in consciousness, and euphoria. Such phenomenological effects (c.f., Garland & Howard 2010) may be particularly evident among youth exhibiting high levels of traits associated with sensation seeking and reward sensitivity, like the helium users identified in this investigation.
Helium users in the present sample evidenced sociodemographic, psychological, and psychiatric characteristics similar to those of adolescent users of volatile solvent inhalants (e.g., Howard et al. 2008; Howard & Jenson 1999). That is, they tended to be predominantly White, to come disproportionately from rural and small town areas, and to evidence more extensive mental health and substance abuse histories, greater psychiatric distress, trauma, and suicidality and more antisocial attitudes and behaviors than their nonusing counterparts. In this investigation, nearly nine of ten youth who attempted to get high using helium also reported inhalation of one or more volatile solvents. Future studies should examine motivations for helium use and identify subtypes of helium users. It may be advisable for ongoing national survey efforts such as the National Survey on Drug Use and Health and the Monitoring the Future study to collect data on helium inhalation. Data regarding the role of helium inhalation in adolescents' emergency department and other health care utilization and in intentional and accidental deaths of adolescents would provide policy makers and practitioners with critically needed information that is not currently available regarding this practice.
This investigation is limited by the cross-sectional and self-report nature of its findings. Nevertheless, project interviewers were carefully trained to assess only helium use that was associated with a specific intent to get high. Thus, we believe the helium users identified in this study had engaged in such inhalation with the specific intent of becoming intoxicated. In the future, however, it would be useful to ask respondents about their lifetime helium use generally and then about the helium inhalation they engaged in with the specific intent of getting high. In our original study, we observed dramatic variability in this sample in the use of 55 different volatile solvents for the purposes of getting high (Howard et al. 2008). Therefore, we believe our assessment of inhalant use is sensitive to differences in levels of use of these agents. Nonetheless, formal psychometric studies of our helium assessment protocol, in terms of reliability and validity,
would be informative.
In sum, this study reports worrisome findings from the first epidemiologic survey of helium use among adolescents. More than one million delinquent youth cycle through juvenile justice treatment facilities annually; extrapolating our findings to this larger population suggests that as many as 115,000 of these youth have inhaled helium with the intention of becoming intoxicated. Like other forms of inhalant misuse, this practice appears to be associated with serious adverse consequences (Garland & Howard 2011) and may be widespread in other clinical, institutionalized, and troubled populations of youth. Future research on all aspects of helium inhalation is needed before an informed judgment can be rendered about the health risks of this practice.
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Ahmed Whitt, M.S.W., Ph.C. (a); Eric L. Garland, Ph.D. (b) & Matthew O. Howard, Ph.D. (c)
Preparation of this report was supported by grants DA021405 (Natural History, Comorbid Mental Disorders, and Consequences of Inhalant Use, M.O. Howard, PI), and DA15929 (Neuropsychiatric Impairments in Adolescent Inhalant Users, M.O. Howard, PI) from the National Institute on Drug Abuse.
(a) Doctoral Candidate, University of North Carolina at Chapel Hill, Chapel Hill, NC.
(b) Assistant Professor, Florida State University, Tallahassee, FL.
(c) Frank A. Daniels Distinguished Professor for Human Services Policy Information, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Please address correspondence to Ahmed Whitt, University of North Carolina, Tate-Turner-Kuralt Building, 325 Pittsboro, CB 3550, Chapel Hill, NC 27599; phone: 919-886-4633; email: email@example.com
TABLE 1 Sociodemographic and Psychiatric Characteristics of Adolescent Helium Users and Nonusers Helium Users Non-Users Helium N = 81 N = 642 Age M (SD) 15.6 (.97) 15.5 (1.27) Gender N (%) Male 66 (81.5) 563 (87.7) Female 15 (18.5) 79 (12.3) Ethnicity N (%) White 68 (85.0) 332 (51.7) African-American 4 (5.0) 234 (36.4) Latino/a 2 (2.5) 26 (4.0) Biracial 5 (6.3) 40 (6.2) Other 1 (1.3) 10 (1.6) Geographic Location of Family Residence N (%) Urban 20 (24.7) 263 (41.0) Suburban 13 (16.0) 87 (13.6) Small Town 38 (46.9) 248 (38.6) Rural 10 (12.3) 44 (6.9) Family Receipt of Welfare N (%) Yes 24 (29.6) 264 (41.7) No 57 (70.4) 369 (58.3) Mental Illness Diagnosis N (%) Yes 61 (75.3) 309 (48.4) No 20 (24.7) 330 (51.6) Auditory Hallucinations N (%) Yes 17 (21.0) 89 (13.9) No 64 (79.0) 553 (86.1) Lifetime Alcohol Use N (%) Yes 78 (96.3) 535 (83.3) No 3 (3.7) 107 (16.7) Lifetime Marijuana Use N (%) Yes 76 (93.8) 550 (85.7) No 5 (6.2) 92 (14.3) Test Statistic Effect Size Age M (SD) t (721) = 0.94 d = 0.94 Gender N (%) [chi square] V = 0.12 (1) = 2.46 Male Female Ethnicity N (%) [chi square] V = 0.22 (4) = 36.05 *** White African-American Latino/a Biracial Other Geographic [chi square] V = 0.11 Location of (3) = 9.34 * Family Residence N (%) Urban Suburban Small Town Rural Family Receipt [chi square] V = 0.08 of Welfare N (%) (1) = 4.35 * Yes No Mental Illness [chi square] V = 0.17 Diagnosis N (%) (1) = 20.90 *** Yes No Auditory [chi square] V = 0.06 Hallucinations (1) = 2.92 N (%) Yes No Lifetime Alcohol [chi square] V = 0.11 Use N (%) (1) = 9.34 ** Yes No Lifetime [chi square] V = 0.11 Marijuana Use (1) = 4.12 * N (%) Yes No d = Cohen's d; V = Cramer's V; * p < .05, ** p < .01, *** p < .001 Note: Number of participant responses differs per question based on nonresponse. TABLE 2 Differences Between Lifetime Helium Users and Nonusers Across Psychiatric and Psychosocial Characteristics Helium Users Nonusers of Helium N = 81 N = 642 Brief Symptom Inventory Global Severity Index 65.3 (40.8) 41.1 (33.1) Anxiety 7.2 (6.0) 4.0 (4.4) Depression 7.6 (6.1) 4.4 (4.8) Hostility 8.3 (5.5) 5.8 (4.8) Interpersonal Sensitivity 4.3 (4.6) 2.7 (3.2) Obsessive-Compulsive 10.0 (6.3) 6.2 (5.1) Paranoid Ideation 8.4 (4.9) 6.0 (4.6) Phobic Anxiety 2.7 (4.0) 1.9 (3.1) Psychoticism 5.8 (4.9) 3.4 (3.6) Somatization 5.8 (5.3) 3.3 (4.2) Massachusetts Youth Screening Instrument Suicidal Experiences Scale 3.4 (2.5) 2.1 (2.3) Traumatic Experiences Scale 3.5 (1.6) 2.9 (1.6) Psychopathic Personality Inventory PPI Total 142.8 (12.5) 135.6 (14.0) Blame Externalization 19.6 (4.6) 18.1 (4.8) Carefree Nonplanfulness 15.6 (4.0) 14.1 (3.9) Coldheartedness 14.5 (4.3) 15.3 (4.6) Fearlessness 20.3 (4.6) 16.7 (5.2) Impulsive Nonconformity 15.9 (4.2) 14.6 (4.1) Machievellian Egocentricity 18.4 (4.4) 17.1 (4.5) Social Potency 20.4 (4.2) 20.7 (4.1) Stress Immunity 18.3 (4.8) 19.1 (4.3) Antisocial Process Screening Device APSD Total 17.6 (5.5) 16.1 (5.5) Self-Report of Delinquency Scale SRD Total 30.9 (18.6) 23.6 (18.3) Test Statistic Effect Size Brief Symptom Inventory Global Severity Index t(93.76) = 5.13 *** d = 1.05 Anxiety t(91.11) = 4.62 *** d = 0.96 Depression t(92.94) = 4.52 *** d = 0.93 Hostility t(96.08) = 3.94 *** d = 0.80 Interpersonal Sensitivity t(90.00) = 3.08 *** d = 0.65 Obsessive-Compulsive t(93.96) = 5.22 *** d = 1.10 Paranoid Ideation t(721) = 4.35 *** d = 0.33 Phobic Anxiety t(92.64) = 1.73 d = 0.35 Psychoticism t(91.52) = 4.45 *** d = 0.92 Somatization t(93.05) = 4.00 *** d = 0.83 Massachusetts Youth Screening Instrument Suicidal Experiences Scale t(98.23) = 4.56 *** d = 0.92 Traumatic Experiences Scale t(720) = 3.20 ** d = 0.24 Psychopathic Personality Inventory PPI Total t(721) = 4.41 *** d = 0.33 Blame Externalization t(721) = 2.66 ** d = 0.20 Carefree Nonplanfulness t(721) = 3.26 *** d = 0.24 Coldheartedness t(721) = 1.52 d = 0.11 Fearlessness t(721) = 5.96 *** d = 0.44 Impulsive Nonconformity t(721) = 2.61 * d = 0.19 Machievellian Egocentricity t(721) = 2.55 * d = 0.19 Social Potency t(721) = 0.71 d = 0.05 Stress Immunity t(721) = 1.59 d = 0.12 Antisocial Process Screening Device APSD Total t(721) = 2.38 * d = 0.18 Self-Report of Delinquency Scale SRD Total t(721) = 3.37 ** d = 0.25 d = Cohen's d; * p < .05, ** p < .01, *** p < .001 TABLE 3 Multiple Logistic Regression Analysis Examining Sociodemographic, Psychiatric, Psychological, and Behavioral Correlates of Lifetime Helium Use in 723 Adolescents 95% Confidence Interval Odds Ratio Lower Upper Race/Ethnicity 5.41 *** 2.69 10.90 Mental Illness Diagnosis 1.61 0.89 2.93 PPI Total Score 1.02 * 1.00 1.04 MAYSI-2 Suicidality Scale 1.04 0.92 1.17 MAYSI-2 Traumatic Experiences Scale 1.06 0.88 1.28 BSI Global Severity Index 1.01 ** 1.01 1.02 APSD Total Score 0.95 0.90 1.01 SRD Total Score 1.02 * 1.00 1.03 Note: Race/Ethnicity is dummy coded as a dichotomous variable with 0 = non-White as the reference category. PPI = Psychopathic Personality Inventory; MAYSI-2 = Massachusetts Youth Screening Instrument, 2nd Version; APSD = Antisocial Process Screening Device; SRD= Self-Report of Delinquency Scale. * p< .05, ** p< .01, *** p< .001.
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|Author:||Whitt, Ahmed; Garland, Eric L.; Howard, Matthew O.|
|Publication:||Journal of Psychoactive Drugs|
|Date:||Dec 1, 2012|
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