Reliability of use, abuse, and dependence of four types of inhalants in adolescents and young adults

The Effects of the Inhalant Toluene on Cognitive Function and Behavioral Flexibility: A Review of Recent Findings

Substance use disorder (SUD) is characterized, in part, by lack of control over drug seeking and taking. The prefrontal cortex (PFC) is highly involved in control of behavior and deficits in PFC structure and function have been demonstrated in clinical and preclinical studies of SUD. Of the various classes of drugs associated with the development of SUD, inhalants are among the least studied despite their widespread use among adolescents and children. In this work, we review what is currently known regarding the sites and mechanisms of action of inhalants with a focus on the volatile solvent toluene that is contained in a wide variety of legal and easily obtained products. We then describe how inhalants including toluene affect various behaviors with an emphasis on those associated with PFC function and how chronic use of inhalants alters brain structure and neuronal signaling. Findings from these studies highlight advances made in recent years that have expanded our understanding of the effects of inhalants on brain structure and reinforce the need for continued work in this field.

Neuropsychiatric characterization of individuals with inhalant use disorder and polysubstance use according to latent profiles of executive functioning

BACKGROUND

Inhalant use disorder (IUD) is associated with deficits in executive functions (EFs). We described latent profiles of EFs and distribution of neuropsychiatric disorders and patterns of severity of use across these profiles.

METHODS

Individuals with IUD were recruited at community-based residential facilities for substance use treatment in Mexico City. Latent profile analysis was conducted with the following tasks: self-ordered pointing, Stroop, Iowa gambling, Wisconsin Card Sorting and Tower of Hanoi.

RESULTS

Three latent profiles were extracted from n = 165: lowest performances of inhibition of response and processing speed; lowest performance of self-monitoring, intermediate performance of inhibition of response and relatively spared processing speed; and intermediate performance of processing speed and self-monitoring, and relatively spared inhibition of response.

CONCLUSION

Between-group differences were observed mainly for antisocial personality disorder and lifetime suicidal. Findings remark the need for identifying distinct profiles of EFs within these populations to better understand the transdiagnostic heterogeneity of EFs.

Overview on Prevalence and Recent Trends in Adolescent Substance Use and Abuse

Substance use and consequent disorders have burdened US health care, criminal justice, and society at large for centuries. Pathological substance use almost invariably begins before 25 years of age, demonstrating how critical adolescence is within the etiology, prevention, and treatment of substance use disorder. This article provides a high-level overview of the prevalence of substance use disorders to provide a context within which the remaining issue provides in-depth descriptions of the evidence on specific topics. Described herein are trends in substance use, substance use disorder, and demographic comparisons.

Cyclohexane, a Potential Drug of Abuse with Pernicious Effects on the Brain

Cyclohexane is a volatile solvent used as a harmless substitute for dangerous organic solvents in several products, such as paint thinners, gasoline and adhesives. Many of these products are used as drugs of abuse and can severely damage neural tissue and impair neurological functions. However, there is very little information on the effects of cyclohexane on the brain. In humans, cyclohexane produces headaches, sleepiness, dizziness, limb weakness, motor changes, and verbal memory impairment. Recent studies in mice have demonstrated behavioral alterations, reactive gliosis, microglial reactivity, and oxidative stress in the brains of cyclohexane-exposed animals. This indicates that cyclohexane may represent a potential problem for public health. Therefore, studies are needed to clarify the neurobiological effects of this volatile compound, including the cellular and molecular mechanisms of neurotoxicity, and to minimize the human health risk posed by the intentional or accidental inhalation of this potential drug of abuse.

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.

Commonalities and Differences Across Substance Use Disorders: Phenomenological and Epidemiological Aspects

BACKGROUND

Although psychoactive substances vary in many ways, they have important commonalties, particularly in their ability to lead to an addiction syndrome. The field lacks an updated review of the commonalities and differences in the phenomenology of alcohol, cannabis, tobacco, stimulants, opioids, hallucinogens, sedatives/tranquilizers, and inhalants and their related substance use disorders (SUDs).

METHODS

DSM-IV and DSM-5 SUD diagnostic criteria were reviewed, as was evidence from recent epidemiological and clinical research: psychometric studies (test-retest reliability, latent trait analysis); physiological indicators (tolerance, withdrawal); prevalence and age of onset. Information was incorporated from previous reviews, PubMed and Scopus literature searches, and data from large U.S. national surveys.

RESULTS

Empirical evidence in the form of test-retest reliability and unidimensionality supports use of the same DSM-IV dependence or DSM-5 SUD diagnostic criteria across substances. For most substances, the criteria sets were generally most informative in general population samples at moderate-to-severe levels of SUD. Across substances, 2 criteria (tolerance and use in hazardous situations) were identified as functioning differently in population subgroups. Since substances have different pharmacological effects, withdrawal is assessed using substance-specific symptoms, while tolerance is not; issues remain with the assessment of tolerance. Alcohol, tobacco, and cannabis were consistently identified as the substances with earliest onset of use, highest prevalence of lifetime use, and highest prevalence of lifetime disorder.

CONCLUSIONS

Despite differences between psychoactive substances, the generic DSM criteria set appears equally applicable across substances. Additional studies of tolerance and hazardous use will be useful for future nosologies. Alcohol, cannabis, and tobacco are the substances with the greatest public health impact due to the high prevalence and early onset of their use, and the potential all 3 substances have to lead to addiction.

Does DSM-5 nomenclature for inhalant use disorder improve upon DSM-IV?

Among drug classes, substance use disorder (SUD) consequent to using inhalants (SUD-I) has perhaps the smallest evidence base. This study compared DSM-IV versus DSM-5 nomenclatures, testing whether 4 traditional categories of inhalants (aerosols, gases, nitrites, solvents) are manifestations of a single pathology, obtaining item parameters of SUD-I criteria, and presenting evidence that SUD can result from using nitrites. An urban, Midwestern, community sample of 162 inhalant users was recruited. Participants were 2/3 male, nearly 85% White, and had a mean age of 20.3 years (SD = 2.4 years), spanning the ages of greatest incidence of SUD and slightly older than the primary ages of inhalants use initiation. Analyses consisted of bivariate associations, principle components analysis, and item response theory analysis. Validity was demonstrated for SUD-I consequent to each inhalant type as well as for aggregating all inhalant types into a single drug class. Results supported DSM-5 nomenclature over DSM-IV in multiple ways except that occurrence of diagnostic orphans was not statistically smaller using DSM-5. (PsycINFO Database Record

Effects of acute and chronic inhalation of paint thinner in mice: behavioral and immunohistochemical study

Abuse of volatile inhalants has become a worldwide issue mainly among adolescents of low income social class. Acute and chronic exposure to these substances results in serious neurological and behavioral impairments. Although real exposure consists largely of simultaneous inhalation of multiple solvents, the vast majority of basic research studies have evaluated the actions of a single volatile component leaving the behavioral and neuronal effects of chemical mixture not fully understood. In this study, we investigated the acute behavioral effects of 300, 450 and 600 ppm of paint thinner inhalation on anxiety, locomotor activity and spatial memory. Additionally, the cognitive impairments related to chronic exposure of the same concentrations of thinner for 45 days were assessed. To understand the neuronal correlates of acute exposure to thinner, we used c-Fos immunohistochemistry as an endogenous marker of neuronal activation following 600 ppm of thinner. The results reveal that (i) chronically thinner exposed mice showed cognitive deficits in Morris water maze and object recognition tasks; (ii) acute inhalation of thinner induces a wide range of behavioral changes. These changes include an anxiolytic effect toward the aversive environmental bright light and a dose dependent effect on explorative locomotion. The wide range of behavioral alterations induced by acute thinner inhalation is consistent with the widespread distribution of thinner-induced c-Fos expression in multiple brain structures.

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.

DSM-5 criteria for substance use disorders: recommendations and rationale

Since DSM-IV was published in 1994, its approach to substance use disorders has come under scrutiny. Strengths were identified (notably, reliability and validity of dependence), but concerns have also arisen. The DSM-5 Substance-Related Disorders Work Group considered these issues and recommended revisions for DSM-5. General concerns included whether to retain the division into two main disorders (dependence and abuse), whether substance use disorder criteria should be added or removed, and whether an appropriate substance use disorder severity indicator could be identified. Specific issues included possible addition of withdrawal syndromes for several substances, alignment of nicotine criteria with those for other substances, addition of biomarkers, and inclusion of nonsubstance, behavioral addictions.This article presents the major issues and evidence considered by the work group, which included literature reviews and extensive new data analyses. The work group recommendations for DSM-5 revisions included combining abuse and dependence criteria into a single substance use disorder based on consistent findings from over 200,000 study participants, dropping legal problems and adding craving as criteria, adding cannabis and caffeine withdrawal syndromes, aligning tobacco use disorder criteria with other substance use disorders, and moving gambling disorders to the chapter formerly reserved for substance-related disorders. The proposed changes overcome many problems, while further studies will be needed to address issues for which less data were available.

Volatile substance misuse : clinical considerations, neuropsychopharmacology and potential role of pharmacotherapy in management

Volatile substance misuse is among the most prevalent and toxic forms of psychoactive drug use, and often results in highly deleterious social, psychological and medical consequences. The prevalence of this pernicious form of substance misuse owes in part to the fact that volatile substances of misuse are ubiquitous in the natural environment. Commonly misused commercial products include glue, shoe polish, nail polish remover, butane lighter fluid, gasoline and computer duster spray. National samples of volatile substance misusers tend to exhibit high rates of psychiatric problems and antisocial behaviour. In addition, cognitive impairments and affective dysregulation are often observed among these individuals. Volatile substances exert their complex neuropharmacological effects on dopaminergic, glutamatergic, GABAergic and serotoninergic receptor systems, as well as on cell membranes and ion channels. Concomitantly, pharmacotherapies for volatile substance abuse might profitably target a number of mechanisms, including reward circuitry in the brain, symptoms of craving and withdrawal, neuropsychiatric and emotional impairments that promote volatile substance abuse, and cognitive enhancement to rectify deficits in executive function. This review details the modes of use, subjective effects, epidemiology, adverse consequences, neuropsychopharmacology and drug treatment of volatile substance misuse, and discusses the potential role of novel forms of pharmacological intervention for this oft-overlooked public health threat of epidemic proportions.

Initial development and validation of the checklist of risk behaviours for youth (CORBY)

The purpose of this study was to develop and begin to validate a brief self-report measure, the checklist of risk behaviours for youth (CORBY). This 15-item measure was designed to assess, over a 30-day period, multiple youth risk behaviours associated with mental health and well-being concerns. Early research provides initial support for the reliability and validity of the CORBY, but further research is warranted. The present study is the first to describe a brief survey addressing multiple youth risk behaviours, examining both the severity of health risk and number of behaviours in which youth are engaged. Such a measure may have important implications for both research and clinical applications.

Inhalant use and inhalant use disorders in the United States

More than 22 million Americans age 12 and older have used inhalants, and every year more than 750,000 use inhalants for the first time. Despite the substantial prevalence and serious toxicities of inhalant use, it has been termed "the forgotten epidemic." Inhalant abuse remains the least-studied form of substance abuse, although research on its epidemiology, neurobiology, treatment, and prevention has accelerated in recent years. This review examines current findings in these areas, identifies gaps in the research and clinical literatures pertaining to inhalant use, and discusses future directions for inhalant-related research and practice efforts.

The prevalence and clinical significance of inhalant withdrawal symptoms among a national sample

Background

Inhalants are among the most common and dangerous forms of substance use, but very little research on inhalant use disorders exist. Unlike other substances, the Diagnostic and Statistical Manual, 4th edition (DSM-IV) indicates that inhalants do not have an associated withdrawal syndrome among persons who meet criteria for inhalant dependence.

Methods

Using data from the National Epidemiologic Survey on Alcohol and Related Conditions, this study examines the prevalence of withdrawal symptoms among inhalant users. Prevalence of inhalant withdrawal symptoms for inhalants was also compared with the prevalence of cocaine withdrawal symptoms to help determine the presence of an inhalant withdrawal syndrome.

Results

Approximately 47.8% of persons who met criteria for inhalant dependence reported experiencing three or more inhalant-related withdrawal symptoms that were clinically significant. Among those with inhalant dependence, almost half of the withdrawal symptoms were as common as the corresponding withdrawal symptoms experienced by persons with cocaine dependence. Furthermore, the percentage of persons with inhalant dependence reporting clinically significant inhalant withdrawal symptoms was almost equal to the percentage of persons with cocaine dependence reporting clinically significant cocaine withdrawal symptoms.

Conclusions

These data provide evidence for an inhalant-related withdrawal syndrome among persons with inhalant dependence. Revisions to DSM-IV should consider including inhalant withdrawal as a diagnostic criterion for this disorder.

Item response theory analysis of DSM-IV criteria for inhalant-use disorders in adolescents

OBJECTIVE

Inhalants are a serious public health concern and a dangerous form of substance use. An important unresolved issue in the inhalant literature concerns the validity of inhalant-use diagnoses and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, distinction between inhalant abuse and inhalant dependence. To address these limitations and provide the foundation for helping build stronger diagnostic and assessment tools related to inhalant problems, this study examined the dimensionality of the criteria set and the abuse-dependence distinction using item response theory (IRT) analysis.

METHOD

This study used data from a survey of the population of Missouri Division of Youth Services' residents of the residential treatment system. The current study focused on adolescents and young adults who reported a lifetime history of inhalant use (N = 279).

RESULTS

The results from the IRT analysis showed no consistent hierarchical ordering of abuse and dependence criteria, providing strong evidence against the abuse-dependence distinction. The abuse criterion of legal problems associated with use represented the item with the highest level of inhalant severity. The dependence criterion that was related to giving up important social, occupational, or recreational activities provided the most accurate discrimination between individuals at different levels of severity.

CONCLUSIONS

Inhalant-use disorders are best represented using a dimensional versus a categorical approach. IRT analysis provides guidance for selecting criteria that can be useful for brief assessments of inhalant-use problems.

Volatile substance misuse in the United States

Volatile substance misuse (VSM) is prevalent in the United States and associated with manifold deleterious outcomes. This review summarizes research on: (1) the prevalence of VSM in the United States and its trends since 1975, (2) population subgroups at an elevated risk for VSM, (3) key correlates of VSM, (4) psychosocial consequences of VSM, including emerging public health threats, and (5) etiological and contextual considerations of VSM use. Implications for future research and practice with volatile substance misusers in the United States are identified.

The latest evidence in the neuroscience of solvent misuse: an article written for service providers

This work reviews preclinical and clinical studies published during the past two decades on the cellular and behavioral effects of commonly misused solvents. In animals, acute solvent exposure produces motor impairment and antidepressant- and anxiolytic-like effects. Human intoxication from misusing solvents is similar to that of ethanol; however, hallucinations and sudden sniffing death may occur at high solvent concentrations. Among chronic misusers, there is evidence of impaired memory, increased prevalence of psychiatric disorders, and neurological damage. Solvents facilitate inhibitory neurotransmission and block excitatory mechanisms. Toluene, in particular, increases brain dopamine levels and its effects occur at concentrations that do not dissolve cell membranes; therefore, neuronal damage is not an immediate, unavoidable consequence of solvent misuse.

Inhalant withdrawal as a clinically significant feature of inhalant dependence disorder

Inhalant use is the intentional inhalation of vapors from commercial products or specific chemical agents for the purpose of achieving intoxication. Inhalants are among the most common and pernicious forms of substance use and the least studied of the major drugs. Diagnosis of inhalant dependence, according to the DSM-IV [Weintraub E, Gandhi D, Robinson C. Medical complications due to mothball abuse. South Med J 2000;93:427-9] excludes inhalant withdrawal symptoms, as expert opinion has suggested that an inhalant withdrawal syndrome is neither common nor clinically significant. This article draws from multiple sources of data to suggest that withdrawal symptoms can be part of inhalant dependence and are clinically significant. This hypothesis needs rigorous evaluation to ensure the diagnostic validity of inhalant use disorders.

Adolescent inhalant use, abuse and dependence

AIMS

To compare adolescent inhalant users without DSM-IV inhalant use disorders (IUDs) to youth with IUDs (i.e. abuse or dependence) across demographic, psychosocial and clinical measures.

DESIGN

Cross-sectional survey with structured psychiatric interviews.

SETTING

Facilities (n = 32) comprising the Missouri Division of Youth Services (MDYS) residential treatment system for juvenile offenders. Participants Current MDYS residents (n = 723); 97.7% of residents participated. Most youth were male (87%) and in mid-adolescence (mean = 15.5 years, standard deviation = 1.2, range = 11-20); more than one-third (38.6%, n = 279) reported life-time inhalant use.

MEASUREMENTS

Antisocial behavior, temperament, trauma-exposure, suicidality, psychiatric symptoms and substance-related problems.

FINDINGS

Among life-time inhalant users, 46.9% met criteria for a life-time DSM-IV IUD (inhalant abuse = 18.6%, inhalant dependence = 28.3%). Bivariate analyses showed that, in comparison to non-users, inhalant users with and without an IUD were more likely to be Caucasian, live in rural or small towns, have higher levels of anxiety and depressive symptoms, evidence more impulsive and fearless temperaments and report more past-year antisocial behavior and life-time suicidality, traumatic experiences and global substance use problems. A monotonic relationship between inhalant use, abuse and dependence and adverse outcomes was observed, with comparatively high rates of dysfunction observed among inhalant-dependent youth. Multivariate regression analyses showed that inhalant users with and without an IUD had greater levels of suicidal ideation and substance use problems than non-users.

CONCLUSIONS

Youth with IUDs have personal histories characterized by high levels of trauma, suicidality, psychiatric distress, antisocial behavior and substance-related problems. A monotonic relationship between inhalant use, abuse and dependence and serious adverse outcomes was observed.

A survey of inhalant use disorders among delinquent youth: prevalence, clinical features, and latent structure of DSM-IV diagnostic criteria

BACKGROUND

Inhalant use is among the most pernicious and poorly understood forms of adolescent substance use. Many youth in the juvenile justice system have used inhalants, but little is known about inhalant use disorders (IUDs) in antisocial youth populations. The purpose of this study was to examine the prevalence, clinical features, and latent structure of DSM-IV IUDs in a state population of antisocial youth.

METHODS

Cross-sectional survey conducted in 2003. Of 740 youth residing in Missouri State Division of Youth Services' (MDYS) residential treatment facilities at the time the study was conducted, 723 (97.7%) completed interviews. Eighty-seven percent were male, with a mean age of 15.5 (SD = 1.2). Nearly 4 in 10 youth (38.5%; n = 279) reported lifetime inhalant use. Youth ranged from very mildly to severely antisocial.

RESULTS

Of 279 inhalant users, 52 (18.6%) met DSM-IV inhalant abuse criteria and 79 (28.3%) met inhalant dependence criteria. Five of 10 IUD criteria were met by > 10% of the total sample. Latent class analyses demonstrated a substantial concordance between DSM-IV-defined IUDs and an empirically-derived classification based on responses to DSM-IV IUD diagnostic criteria.

CONCLUSION

IUDs and constituent criteria were prevalent among youth in the juvenile justice system. Two groups of problem inhalant users were identified, symptomatic users-DSM-IV inhalant abuse and highly symptomatic users-DSM-IV inhalant dependence, which differed primarily in severity of inhalant-related problems. Inhalant screening, prevention and treatment efforts in juvenile justice settings are rarely delivered, but critically needed.

Prevalence, timing, and predictors of transitions from inhalant use to inhalant use disorders

BACKGROUND

Few studies of the natural history of DSM-IV inhalant substance use disorders (I-SUDs) have been conducted. This investigation examined the prevalence, timing, and predictors of transitions from inhalant use to formal I-SUDs among inhalant users within a nationally representative sample.

METHODS

Participants were 664 U.S. residents participating in the 2000-2001 National Epidemiologic Survey on Alcohol and Related Conditions who reported lifetime inhalant use. Respondents completed structured interviews assessing DSM-IV psychiatric/substance use disorders. Bivariate and Cox regression analyses were conducted to identify risk factors for transitions from inhalant use to I-SUDs.

RESULTS

Nearly one in five (19.4%) persons initiating inhalant use developed an I-SUD. Most I-SUD transitions were to inhalant abuse rather than inhalant dependence. Risk for development of I-SUDs was greatest in the first year following initiation of inhalant use and low thereafter. Multivariate proportional hazards models indicated that presence of a mood/anxiety disorder (HR=7.7, CI=3.1-18.9) or alcohol use disorder (HR=11.9, CI=5.46-26.00) antedating initiation of inhalant use predicted significantly elevated risk for I-SUDs, whereas being married conferred a lower risk for onset of I-SUDs.

CONCLUSIONS

I-SUDs were relatively common among inhalant users, generally occurred in the year following initiation of inhalant use, and were associated with early-onset mood/anxiety and alcohol use disorders. Given the young average age at onset of inhalant use and the rapidity with which most I-SUDs developed, interventions directed to adolescents who have initiated inhalant use might be effective in reducing the proportion of inhalant users who develop I-SUDs.

Epidemiology of inhalant use

PURPOSE OF REVIEW

The aim of the present article is to review recent research on the prevalence and correlates of inhalant use.

RECENT FINDINGS

During the review period more prevalence studies have been conducted in the developing world, adding information to the ongoing studies that are periodically undertaken in the more developed countries. These studies suggest that inhalant use is widespread among children and adolescents and is increasing among females in the developing and developed world. Not all surveys report inhalants as a separate group from other illegal substances; data by type of inhalants are even rarer, and few studies address abuse or dependence. New evidence suggests lower reliability rates for the diagnostic criteria of dependence as compared with other substances, suggesting the need for a review including the evidence of withdrawal. Studies conducted in the period identify vulnerable groups and suggest an increased risk of injecting drug use, HIV, suicidality and psychiatric disorders among inhalant users.

SUMMARY

The extension of inhalant abuse and its adverse consequences argues for greater efforts to advance classification and to increase knowledge through research, including the evaluation of prevention and treatment models.