Volatile substance misuse in the United States

Adolescent drug use initiation and transition into other drugs: A retrospective longitudinal examination across race/ethnicity

BACKGROUND

Understanding adolescent drug use mechanisms is critical for drug use prevention. Although some theories such as the gateway theory suggest that drug users gradually transition into using more addictive drugs, there is no consensus about such a hypothesis. One important factor that hinders the advancement of knowledge in this area is the scarcity of longitudinal studies examining the type of drugs adolescents initially use and the different pathways adolescents take to transition into using other drugs as they grow older.

METHODS

Using the pooled sample of adolescent dug users (14-17 years old; n = 10,644) from the National Survey on Drug Use and Health (2015-2018), we constructed longitudinal data on adolescents' illicit drug use history other than the use of tobacco and alcohol based on the age of drug initiation. This allowed us to investigate what drugs were initially used by adolescents, how the use of these drugs may have progressed into a new drug, and whether there were racial/ethnic differences in the initiation and progression. The retrospective longitudinal data analyses applied life table method and Cox regression models.

RESULTS

Two thirds of the adolescent drug users initiated their drug use trajectories with marijuana, one quarter with inhalants, and the remaining with hallucinogens, prescription drugs, and hard drugs. Adolescent drug users who initiated with different drugs showed unique trajectories to the use of a new drug. By year 8, the probability of using a new drug was about 40% and 70% to 80% for adolescents who initiated with inhalants and other drugs, respectively. The probability of using a new drug for adolescents who initiated with marijuana and inhalants accumulated stably over time, and its difference with that of other drug users diminished over time. The multivariate Cox regression models suggest the observed discrepancies generally held after controlling for covariates. There were also racial/ethnic differences in adolescent drug use initiation and progression, with Black/African American adolescents being the least likely to switch to the use of a new drug.

CONCLUSION

Adolescents' initial use of marijuana and inhalants may lead to substantial risks of using other drugs over time. It is therefore important to screen adolescent drug use comprehensively and provide early interventions to prevent an escalation to more detrimental drugs. The findings provide new evidence to support aspects of both the gateway and generalized risk drug use theories.

Multianalytical Method Validation for Qualitative and Quantitative Analysis of Solvents of Abuse in Oral Fluid by HS-GC/MS

The use of oral fluid as a biological matrix to monitor the use of drugs of abuse is a global trend because it presents several advantages and good correlation to the blood level. Thus, the present work aimed to develop and validate an analytical method for quantification and detection of solvents used as inhalants of abuse in oral fluid (OF), using Quantisal™ as collector device by headspace and gas chromatography coupled with a mass detector (HS-GC/MS). Chromatographic separation was performed with a ZB-BAC1 column and the total time of analysis was 11.8 min. The method showed good linearity (correlation coefficient higher than 0.99 for all solvents). The limits of detection ranged from 0.05 to 5 mg/L, while the lower limits of quantification ranged from 2.5 to 12.5 mg/L. Accuracy, precision, matrix effect, and residual effect presented satisfactory results, meeting the criteria accepted for the validation of bioanalytical methods. The method showed good selectivity considering that, for solvents coeluting at the same retention time, resolution was performed by the mass detector. The method developed proved to be adequate when applied in OF samples from users of drugs and may be used to monitor the abuse of inhalants in routine forensic analyses.

Adolescent inhalant use prevention, assessment, and treatment: A literature synthesis

Inhalant use refers to the use of substances such as gases, glues, and aerosols in order to achieve intoxication, while inhalant use disorder (IUD) encompasses both DSM-IV-TR criteria for inhalant abuse and dependence. Inhalant use among adolescents is an international public health concern considering the severe medical and cognitive consequences and biopsychosocial correlates. In this paper, we summarize the current state of the literature on inhalant use among adolescents focusing on social context, prevention, assessment, and treatment strategies. Psychoeducation, skills training, and environmental supply reduction are helpful strategies for preventing adolescent inhalant use, while parent and adolescent self-report as well as physician report of medical signs and symptoms can aid in assessment and diagnosis. Although research has only begun to explore the treatment of inhalant use, preliminary findings suggest that a multimodal approach involving individual counselling (i.e., CBT brief intervention), family therapy, and activity and engagement programs is the first-line treatment, with residential treatment programs indicated for more severe presentations. The limited nature of treatments developed specifically for inhalant use combined with high prevalence rates and potential for significant impairment within the adolescent population indicate the need for further research. Research should focus on understanding the social context of use, establishing the efficacy of current adolescent substance use treatments adapted for inhalant use, and exploring long-term outcomes.

Long-Term Prevalence and Demographic Trends in U.S. Adolescent Inhalant Use: Implications for Clinicians and Prevention Scientists

BACKGROUND

Inhalant use by adolescents is cause for concern due to the early age of inhalant use initiation and the many short- and long-term health consequences that can occur concurrently with and subsequent to use. However, inhalant use research has been limited relative to the literature available on other drug use.

OBJECTIVES

The present research examined long-term trends in inhalant use prevalence, demographic risk factors of inhalant use, and median grade level of first use.

METHODS

Monitoring the Future data from 1991 to 2011, which includes information drawn from United States eighth, tenth, and twelfth graders, were examined. The total sample comprised more than one million participants. Results were examined descriptively with figures and quantitatively with mixed-effects regression models of the effect of time on use rates.

RESULTS

Inhalant use prevalence rates generally declined over the selected period. Though rates of use by males and females decreased significantly, the proportion of females among lifetime users increased significantly. Whites, Hispanics, and members of uncategorized "other" ethnicities showed the highest prevalence rates. Although the proportion of Whites among lifetime users decreased significantly, the proportion of Hispanics and "other" ethnicities increased significantly. The median first use was between sixth and ninth grade.

CONCLUSIONS/IMPORTANCE

Results suggest a need to tailor inhalant use treatment and prevention programs to the needs of specific demographic groups and to target interventions early to prevent youth inhalant use. Strengths, limitations, and directions for future research are discussed.

Preclinical characterization of toluene as a non-classical hallucinogen drug in rats: participation of 5-HT, dopamine and glutamate systems

RATIONALE

Toluene is a misused inhalant with hallucinogenic properties and complex effects. Toluene blocks N-methyl-D-aspartate (NMDA) receptors, releases dopamine (DA), and modifies several neurotransmitter levels; nonetheless, the mechanism by which it produces hallucinations is not well characterized.

OBJECTIVES

This study aims (a) to study toluene's effects on the 5-HT2A-mediated head-twitch response (HTR), dopamine (DA), and serotonin (5-HT) tissue levels in discrete brain regions; (b) to compare the actions of toluene, ketamine, and 1-[2,5-dimethoxy-4-iodophenyl]-2-aminopropane (DOI) on HTR; and (c) to study the pharmacological blockade of toluene's and ketamine's effects by selective drugs.

METHODS

Independent groups of rats inhaled toluene (500-12,000 ppm) for 30 min during which the occurrence of serotonergic signs was analyzed. Brains were obtained after exposure to determine DA and 5-HT levels by HPLC.

RESULTS

Toluene concentration-dependently induced HTR. Other serotonin syndrome signs were evident at high concentrations. Toluene (4000 and 8000 ppm), and ketamine (3 and 10 mg/kg), significantly increased 5-HT levels in the frontal cortex (FC) striatum, hippocampus, and brain stem, as well as DA levels in the striatum and FC. Pretreatment with ketanserin (5HT2A/2C receptor antagonist), M100907 (selective 5-HT2A receptor antagonist), D-serine (co-agonist of the NMDA receptor glycine site), and haloperidol (D2 receptor antagonist) significantly decreased toluene's and ketamine's actions. The 5HT1A receptor antagonist WAY100635 had no effect.

CONCLUSION

Toluene stimulates 5HT2A and 5HT2C receptors, and increases 5-HT and DA levels. These actions are similar to those produced by ketamine and involve activation of a complex neurotransmitter network that includes NMDA receptor antagonism.

Patterns of substance use, delinquency, and risk factors among adolescent inhalant users

BACKGROUND

Despite insidious effects, use of inhalant substances by adolescents remains an understudied phenomenon.

OBJECTIVE

This research was designed to identify patterns of past year substance use and delinquency among adolescent inhalant users.

METHOD

The study used a sample of adolescent inhalant users (ages ranged from 12-17 years, n = 7,476) taken from a pooled sample of the 2002 through 2012 National Survey of Drug Use and Health (NSDUH). Three-step latent class analyses were conducted with past year substance use and delinquency behaviors as class indicators. Demographic and social covariates were included in the analyses.

RESULTS

Analyses yielded a six-class solution comprised of classes of users characterized by low substance use/low delinquency, high substance use/low delinquency, low substance use/fighting, cigarettes/alcohol/marijuana, high substance use/high delinquency, and cigarettes/alcohol/ marijuana/opioids/moderate delinquency.

CONCLUSIONS

Findings provide insight into the taxonomy of adolescent inhalant user heterogeneity, and may inform future efforts at detection and prevention of inhalant use by suggesting warning signs of co-occurring externalizing behaviors and possible indications of underlying internalized issues.

Risk for inhalant initiation among middle school students: understanding individual, family, and peer risk and protective factors

OBJECTIVE

Because initiation of inhalants at an early age is associated with a range of health and behavioral problems, including an increased likelihood of inhalant dependence (based on criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), we conducted discrete time survival analyses to determine the role of time-invariant and time-variant (over five waves) risk and protective factors as well as grade in inhalant initiation among middle school students.

METHOD

The current study uses data from 3,215 students who were initially surveyed as sixth graders in 2008-2009 and were resurveyed in seventh and eighth grades. Students were part of a larger substance use prevention trial conducted in greater Los Angeles. The sample is racially/ethnically diverse (54% Hispanic/Latino, 16% Asian, 14% White, 3% African American) and 51% male.

RESULTS

Seventeen percent of youths initiated inhalants during middle school. Higher drug refusal self-efficacy, familism (i.e., values related to family), and parental respect were associated with decreased odds of inhalant initiation. Having a significant adult or older sibling who used substances was associated with increased risk of initiation, but adult influence declined linearly and by the end of seventh grade was no longer a risk factor. Self-rated popularity was associated with inhalant initiation in seventh grade only, and perceived substance use by peers was associated with inhalant initiation in sixth grade only.

CONCLUSIONS

The influence of adults, siblings, and peers on inhalant use may be strongest in sixth and seventh grade. Interventions to prevent inhalant initiation should target sixth and seventh graders, address influence by family and peers, and provide skills training to improve drug refusal self-efficacy.

Outlier populations: individual and social network correlates of solvent-using injection drug users

Objective

We previously identified a high prevalence of Hepatitis C (HCV) amongst solvent-using injection drug users (S-IDU) relative to other injection drug users within the same locality. Here we incorporated social network variables to better characterize some of the behavioural characteristics that may be putting this specific subgroup of IDU at elevated disease risk.

Methods

A cross-sectional survey of at-risk populations was carried out in Winnipeg, Canada in 2009. Individuals reporting any history of injection drug and/or solvent use were included in the study. Associations between subgroup membership, infection with HCV and HIV and individual and social network variables were examined.

Results

In relation to other IDU, S-IDU were more likely to be infected with HCV, to report ever having shared a syringe, and to associate with other IDU. They were further differentiated in terms of their self-reported sexual orientation, ethnicity and in the injection drugs typically used.

Conclusion

Solvent use stands as a proxy measure of numerous other characteristics that put this group of IDU at higher risk of infection. Provision of adequate services to ostracized subpopulations may result in wider population-level benefits.

Volatile solvents as drugs of abuse: focus on the cortico-mesolimbic circuitry

Volatile solvents such as those found in fuels, paints, and thinners are found throughout the world and are used in a variety of industrial applications. However, these compounds are also often intentionally inhaled at high concentrations to produce intoxication. While solvent use has been recognized as a potential drug problem for many years, research on the sites and mechanisms of action of these compounds lags behind that of other drugs of abuse. In this review, we first discuss the epidemiology of voluntary solvent use throughout the world and then consider what is known about their basic pharmacology and how this may explain their use as drugs of abuse. We next present data from preclinical and clinical studies indicating that these substances induce common addiction sequelae such as dependence, withdrawal, and cognitive impairments. We describe how toluene, the most commonly studied psychoactive volatile solvent, alters synaptic transmission in key brain circuits such as the mesolimbic dopamine system and medial prefrontal cortex (mPFC) that are thought to underlie addiction pathology. Finally, we make the case that activity in mPFC circuits is a critical regulator of the mesolimbic dopamine system's ability to respond to volatile solvents like toluene. Overall, this review provides evidence that volatile solvents have high abuse liability because of their selective effects on critical nodes of the addiction neurocircuitry, and underscores the need for more research into how these compounds induce adaptations in neural circuits that underlie addiction pathology.

Psychosocial therapeutic interventions for volatile substance use: a systematic review

AIMS

Volatile substance use (VSU) is associated with a range of adverse outcomes, including cognitive impairment and death. It occurs disproportionately within young and marginalized populations. A previous international systematic review of VSU treatment identified no relevant studies. This paper reports on a systematic review of a range of study types concerning psychosocial interventions for VSU.

METHODS

Search parameters were developed using the Population, Intervention, Professionals, Outcomes, Health care setting and Contexts (PIPOH) tool with input from an expert committee. Included were randomized controlled trials (RCTs), comparative studies with or without concurrent controls, case series studies and grey literature, published in English during 1980-2010.

RESULTS

The initial search identified 2344 references. After two screening phases, 23 studies of VSU therapeutic interventions remained. Of these, 19 concerned psychosocial interventions, which we discuss as: case management; counselling; recreation and engagement programmes; and residential treatment. Studies were conducted in Australia, Canada, the United States, United Kingdom and Brazil. No RCTs were identified and studies were generally of low evidentiary levels.

CONCLUSIONS

Even when a range of study types are included, clear conclusions for volatile substance use psychological treatment are not supported, but three intervention types merit further examination: family therapy, activity-based programmes and Indigenous-led residential approaches. Future volatile substance use research could be enhanced by developing and validating outcome measurement tools. Robust multi-site studies are also required.