Additional information on inhalant-related disorders
Additional Information on Inhalant-Related Disorders
Associated Features and Disorders
Associated descriptive features and mental disorders.
Individuals with Inhalant Intoxication may present with auditory, visual, or tactile hallucinations or other perceptual disturbances (macropsia, micropsia, illusionary misperceptions, alterations in time perception). Delusions (such as believing one can fly) may develop during periods of Inhalant Intoxication, especially those characterized by marked confusion; in some cases, these delusions may be acted on with resultant injury. Anxiety may also be present. Repeated but episodic intake of inhalants may first be associated with school problems (e.g., truancy, poor grades, dropping out of school) as well as family conflict. Use by older adolescents and young adults is often associated with social and work problems (e.g., delinquency, unemployment). Most commonly, inhalants are used by adolescents in a group setting. Solitary use tends to be more typical of those with long-term, heavy use. The use of inhalants as the predominant substance among those seeking help for Substance Dependence appears to be rare, but inhalants may be a secondary drug used by individuals with Dependence on other substances. In some individuals, there may be a progression to a stage at which inhalants become the preferred substance, especially among individuals with Antisocial Personality Disorder.
Associated laboratory findings.
Direct assay for inhalants is not generally available and is not part of routine screening for drugs of abuse. However, a metabolite of toluene, hippuric acid, is excreted in the urine, and a ratio greater than 1 in relation to creatinine might be suggestive of toluene use. Damage to muscles, kidneys, liver, and other organs can result in laboratory tests being indicative of these pathological conditions.
Associated physical examination findings and general medical conditions.
The odor of paint or solvents may be present on the breath or clothes of individuals who use inhalants, or there may be a residue of the substance on clothing or skin. A "glue sniffer's rash" may be evident around the nose and mouth, and conjunctival irritation may be noted. There may be evidence of trauma due to disinhibited behavior or burns due to the flammable nature of these compounds. Nonspecific respiratory findings include evidence of upper- or lower-airway irritation, including increased airway resistance, pulmonary hypertension, acute respiratory distress, coughing, sinus discharge, dyspnea, rales, or rhonchi; rarely, cyanosis may result from pneumonitis or asphyxia. There may also be headache, generalized weakness, abdominal pain, nausea, and vomiting.
Inhalants can cause both central and peripheral nervous system damage, which may be permanent. Examination of the individual who chronically uses inhalants may reveal a number of neurological deficits, including generalized weakness and peripheral neuropathies. Cerebral atrophy, cerebellar degeneration, and white matter lesions resulting in cranial nerve or pyramidal tract signs have been reported among individuals with heavy use. Recurrent use may lead to the development of hepatitis (which may progress to cirrhosis) or metabolic acidosis consistent with distal renal tubular acidosis. Chronic renal failure, hepatorenal syndrome, and proximal renal tubular acidosis have also been reported, as has bone marrow suppression, especially with benzene and trichloroethylene, with the former possibly increasing the risk for acute myelocytic leukemia. Some inhalants (e.g., methylene chloride) may be metabolized to carbon monoxide. Death may occur from respiratory or cardiovascular depression; in particular, "sudden sniffing death" may result from acute arrhythmia, hypoxia, or electrolyte abnormalities.
Specific Culture, Age, and Gender Features
While most surveys report few differences based solely on ethnic or racial groups, a study of children in rural Alaska noted that almost 50% of Alaskan-native children in isolated villages have at some time used solvents to get high. Because of their low cost and easy availability, inhalants are often the first drugs of experimentation for young people, and there may be a higher incidence among those living in economically depressed areas. Inhalant use may begin by ages 9-12 years, appears to peak in adolescence, and is less common after age 35 years. Males account for 70%-80% of inhalant-related emergency-room visits.
Prevalence
It is difficult to establish the true prevalence of inhalant use because these drugs are easy to obtain legally, and their importance might be underestimated in surveys. In addition, the popularity of different inhalants changes over time, with, for example, a decrease over the past decade in the proportion of users preferring glues and aerosols and an increase in those inhaling lighter fluid.
A 1996 national survey of drug use reported that around 6% of people in the United States acknowledged ever having used inhalants, with 1% reporting use in the past year and 0.4% in the past month. The highest lifetime prevalence was seen for 18- to 25-year-olds (11%), while 12- to 17-year-olds predominated for use in the prior year (4%) or in the prior month (2%). Higher rates are reported among a variety of subgroups, including almost 30% of prison inmates who report ever having used these substances. Rates of use are also higher among populations who live in poverty, especially children and young adults. It should be noted that because these surveys measured patterns of use rather than disorders, it is not known how many of those in the survey who used inhalants had symptoms that met criteria for Dependence or Abuse. The prevalence of Inhalant Dependence or Abuse in the general population is unknown.
Course
It can be difficult to match inhalant dose to effect because the different methods of administration and the varying concentrations of inhalants in the products used cause highly variable concentrations in the body. The time course of Inhalant Intoxication is related to the pharmacological characteristics of the specific substance used, but it is typically brief, lasting from a few minutes to an hour. Onset is rapid, peaking within a few minutes after inhaling. Younger children diagnosed as having Inhalant Dependence may use inhalants several times a week, often on weekends and after school. Severe dependence in adults may involve varying periods of intoxication throughout each day and occasional periods of heavier use that may last several days. This pattern may persist for years, with recurrent need for treatment. Individuals who use inhalants may have a preferred level or degree of intoxication, and the method of administration (typically sniffing from a container or breathing through a rag soaked in the substance) may allow the individual to maintain that level for several hours. Cases have also been reported of the development of Dependence in industrial workers who have long-term occupational exposure and access to inhalants. A worker may begin to use the compound for its psychoactive effects and subsequently develop a pattern of Dependence. Use leading to Dependence may also occur in people who do not have access to other substances (e.g., prisoners, isolated military personnel, and adolescents or young adults in isolated rural areas).
Differential Diagnosis
For a general discussion of the differential diagnosis of Substance-Related Disorders, see p. 207. Inhalant-Induced Disorders may be characterized by symptoms (e.g., depressed mood) that resemble primary mental disorders (e.g., Major Depressive Disorder versus Inhalant-Induced Mood Disorder, With Depressive Features, With Onset During Intoxication). See p. 210 for a discussion of this differential diagnosis.
The symptoms of mild to moderate Inhalant Intoxication can be similar to those of Alcohol Intoxication and Sedative, Hypnotic, or Anxiolytic Intoxication. Breath odor or residues on body or clothing may be important differentiating clues, but should not be relied on exclusively. Individuals who chronically use inhalants are likely to use other substances frequently and heavily, further complicating the diagnostic picture. Concomitant use of alcohol may also make the differentiation difficult. History of the drug used and characteristic findings (including odor of solvent or paint residue) may differentiate Inhalant Intoxication from other substance intoxications; additionally, symptoms may subside faster with Inhalant Intoxication than with other substance intoxications. Rapid onset and resolution may also differentiate Inhalant Intoxication from other mental disorders and neurological conditions. Inhalant Intoxication is distinguished from the other Inhalant-Induced Disorders (e.g., Inhalant-Induced Mood Disorder, With Onset During Intoxication) because the symptoms in these latter disorders are in excess of those usually associated with Inhalant Intoxication and are severe enough to warrant independent clinical attention.
Industrial workers may occasionally be accidentally exposed to volatile chemicals and suffer physiological intoxication. The category "Other Substance-Related Disorders" should be used for such toxin exposures.