Substance Abuse

Etiology

Substance abuse has multifactorial origins ( Fig. 140.3 ). Biologic factors, including genetic predisposition, are established contributors. Behaviors such as rebelliousness, poor school performance, delinquency, and criminal activity and personality traits such as low self-esteem, anxiety, and lack of self-control are frequently associated with or predate the onset of drug use. Psychiatric disorders often coexist with adolescent substance use. Conduct disorders and antisocial personality disorders are the most common diagnoses coexisting with substance abuse, particularly in males. Teens with depression (see Chapter 39.1 ), attention deficit disorder ( Chapter 49 ), anxiety ( Chapter 38 ), and eating disorders ( Chapter 41 ) have high rates of substance use. The determinants of adolescent substance use and abuse are explained using numerous theoretical models, with factors at the individual level, the level of significant relationships with others, and the level of the setting or environment. Models include a balance of risk and protective or coping factors contributing to individual differences among adolescents with similar risk factors who escape adverse outcomes.

Risk factors for adolescent drug use may differ from those associated with adolescent drug abuse . Adolescent use is more commonly related to social and peer factors, whereas abuse is more often a function of psychological and biologic factors. The likelihood that an otherwise normal adolescent would experiment with drugs may depend on the availability of the drug to the adolescent, the perceived positive or otherwise functional value to the adolescent, the perceived risk associated with use, and the presence or absence of restraints, as determined by the adolescent's cultural or other important value systems. An adolescent who abuses drugs may have genetic or biologic factors coexisting with dependence on a particular drug for coping with day-to-day activities.

Specific historical questions can assist in determining the severity of the drug problem through a rating system ( Table 140.1 ). The type of drug used (marijuana vs heroin), the circumstances of use (alone or in a group setting), the frequency and timing of use (daily before school vs occasionally on a weekend), current mental health status, and general functional status, including sleep habits and screen use, should all be considered in evaluating any child or adolescent found to be using a drug. The stage of drug use/abuse should also be considered ( Table 140.2 ). A teen may spend months or years in the experimentation phase trying a variety of illicit substances, including the most common drugs: cigarettes, alcohol, and marijuana. Often it is not until regular use of drugs resulting in negative consequences (problem use) that the teen is identified as having a problem, either by parents, friends, teachers, or a healthcare provider. Certain protective factors play a part in buffering the risk factors as well as assisting in anticipating the long-term outcome of experimentation. Having emotionally supportive parents with open communication styles, involvement in organized school activities, having mentors or role models outside the home, and recognition of the importance of academic achievement are examples of the important protective factors.

Epidemiology

Alcohol, cigarettes, and marijuana are the most commonly reported substances used among U.S. teens ( Table 140.3 ). The prevalence of substance use and associated risky behaviors vary by age, gender, race/ethnicity, and other sociodemographic factors. Younger teenagers tend to report less use of drugs than do older teenagers, except for inhalants (in 2016, 4.4% in 8th grade, 2.8% in 10th grade, 1.0% in 12th grade). Males have higher rates of both licit and illicit drug use than females, with greatest differences seen in their higher rates of frequent use of smokeless tobacco, cigars, and anabolic steroids. For a number of years, black 12th graders have reported lifetime, annual, 30-day, and daily prevalence levels for nearly all drugs that were lower than those for white or Hispanic 12th graders. That is less true today, with levels of drug use among blacks more similar to the other groups.

The distribution of annual marijuana use by race/ethnicity varies by grade level. In all 3 grades, prevalence is highest among Hispanic students. Differences in prevalence across the groups are proportionately largest in 8th grade (13% for Hispanics, 7.8% for whites), somewhat smaller in 10th grade (27% for Hispanics, 24% for whites), and negligible in 12th grade (37% for Hispanics, 35% for whites). Blacks fall between whites and Hispanics in 8th and 10th grade but are slightly below them in 12th grade (35%).

The number of 12th graders who report using any of the prescription psychotherapeutic drugs, including amphetamines, sedatives (barbiturates), tranquilizers, and narcotics other than heroin, decreased in 2016 ( Table 140.4 ). Prevalence was 18.0%, 12.0%, and 5.4% for lifetime, annual, and 30-day use, respectively, indicating that a substantial portion of adolescents still use prescription drugs nonmedically. Rural adolescents were 26% more likely than urban adolescents to have used prescription drugs nonmedically. Use was associated with decreased health status, major depressive episode(s), and other drug use (marijuana, cocaine, hallucinogens, inhalants) and alcohol use. In a large-scale study of 16,209 adolescent exposures to prescription drugs, 52.4% were females, and the mean age was 16.6 yr. The 5 most frequently misused or abused drugs were hydrocodone (32%), amphetamines (18%), oxycodone (15%), methylphenidate (14%), and tramadol (11%). Many of these drugs can be found in the parents' home, some are over-the-counter (OTC) drugs (dextromethorphan, pseudoephedrine), whereas others are purchased from drug dealers at schools and colleges. Teen users of nonmedical opioids use other substances concurrently. Most frequently, teens combine opioids with marijuana, alcohol, cocaine, and tranquilizers, putting them at risk for serious complications and overdose.

Table 140.4

Commonly Abused Prescription Drugs

Courtesy of the National Institute on Drug Abuse, US Department of Health and Human Services, National Institutes of Health. www.drugabuse.gov .

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Clinical Manifestations

Although manifestations vary by the specific substance of use, adolescents who use drugs often present in an office setting with no obvious physical findings. Drug use is more frequently detected in adolescents who experience trauma such as motor vehicle crashes, bicycle injuries, or violence. Eliciting appropriate historical information regarding substance use, followed by blood alcohol and urine drug screens, is recommended in emergency settings. Although waning in popularity, the illicit substances known as “club drugs” still need to be considered in the differential diagnosis of a teen with an altered sensorium ( Table 140.5 ). An adolescent presenting to an emergency setting with an impaired sensorium should be evaluated for substance use as a part of the differential diagnosis ( Table 140.6 ). Screening for substance use is recommended for patients with psychiatric and behavioral diagnoses. Other clinical manifestations of substance use are associated with the route of use; intravenous drug use is associated with venous “tracks” and needle marks, and nasal mucosal injuries are associated with nasal insufflation of drugs. Seizures can be a direct effect of drugs such as cocaine, synthetic marijuana, and amphetamines or an effect of drug withdrawal in the case of barbiturates or tranquilizers.

Screening for Substance Abuse Disorders

In a primary care setting the annual health maintenance examination provides an opportunity for identifying adolescents with substance use or abuse issues. The direct questions as well as the assessment of school performance, family relationships, and peer activities may necessitate a more in-depth interview if there are suggestions of difficulties in those areas. Several self-report screening questionnaires also are available, with varying degrees of standardization, length, and reliability. The CRAFFT mnemonic is specifically designed to screen for adolescents' substance use in the primary setting ( Table 140.7 ). Privacy and confidentiality must be established when asking the teen about specifics of their substance experimentation or use. Interviewing the parents can provide additional perspective on early warning signs that go unnoticed or disregarded by the teen. Examples of early warning signs of teen substance use are change in mood, appetite, or sleep pattern; decreased interest in school or school performance; loss of weight; secretive behavior about social plans; or valuables such as money or jewelry missing from the home. The use of urine drug screening is recommended when select circumstances are present: (1) psychiatric symptoms to rule out comorbidity or dual diagnoses, (2) significant changes in school performance or other daily behaviors, (3) frequently occurring accidents, (4) frequently occurring episodes of respiratory problems, (5) evaluation of serious motor vehicular or other injuries, and (6) as a monitoring procedure for a recovery program. Table 140.8 shows common tests used for detection by substance, along with the approximate retention time between use and identification in the urine. Most initial screening uses an immunoassay method, such as the enzyme-multiplied immunoassay technique, followed by a confirmatory test using highly sensitive, highly specific gas chromatography–mass spectrometry. The substances that can cause false-positive results should be considered, especially when there is a discrepancy between the physical findings and the urine drug screen result. In 2007 the American of Academy of Pediatrics (AAP) released guidelines that strongly discourage routine home-based or school-based testing.

Diagnosis

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) no longer identifies substance use disorders as those of abuse or of dependence . A substance use disorder is defined by a cluster of cognitive, behavioral, and physiologic symptoms that indicate that an adolescent is using a substance even though there is evidence that the substance is harming the adolescent. Even after detoxification, a substance use disorder may leave persisting changes in brain circuits with resulting behavioral changes. There are 11 criteria that describe a pathologic pattern of behaviors related to use of the substance, falling into 4 categories: impaired control, social impairment, increased risk, and pharmacologic criteria. The 1st category, impaired control , describes an individual taking increasing amounts of the substance who expresses a persistent desire to decrease use, with unsuccessful efforts. The individual may spend a great deal of time obtaining the substance, using the substance, or recovering from its effects and expresses an intense desire for the drug, usually in settings where the drug had been available, such as a specific type of social situation. The 2nd cluster of criteria (5-7) reflects social impairment, including the inability to perform as expected in school, at home, or at a job; increasing social problems; and withdrawing from the family. The 3rd cluster of 2 criteria addresses increased risk associated with use of the substance, and the 4th cluster includes 2 criteria addressing pharmacologic responses (tolerance and/or withdrawal). The total number of criteria present is associated with a determination of a mild, moderate, or severe disorder.

These criteria may have limitations with adolescents because of differing patterns of use, developmental implications, and other age-related consequences. Adolescents who meet diagnostic criteria should be referred to a program for substance use disorder treatment unless the primary care physician has additional training in addiction medicine.

Complications

Substance use in adolescence is associated with comorbidities and acts of juvenile delinquency. Youth may engage in other high-risk behaviors such as robbery, burglary, drug dealing, or prostitution for the purpose of acquiring the money necessary to buy drugs or alcohol. Regular use of any drug eventually diminishes judgment and is associated with unprotected sexual activity with its consequences of pregnancy and sexually transmitted infections, including HIV, as well as physical violence and trauma. Drug and alcohol use is closely associated with trauma in the adolescent population. Several studies of adolescent trauma victims have identified cannabinoids and cocaine in blood and urine samples in significant proportions (40%), in addition to the more common identification of alcohol. Any use of injected substances involves the risk of hepatitis B and C viruses as well as HIV (see Chapter 302 ).

Treatment

Adolescent drug abuse is a complex condition requiring a multidisciplinary approach that attends to the needs of the individual, not just drug use. Fundamental principles for treatment include accessibility to treatment; utilizing a multidisciplinary approach; employing individual or group counseling; offering mental health services; monitoring of drug use while in treatment; and understanding that recovery from drug abuse/addiction may involve multiple relapses. For most patients, remaining in treatment for a minimum period of 3 mo will result in a significant improvement.

Prognosis

For adolescent substance abusers who have been referred to a drug treatment program, positive outcomes are directly related to regular attendance in posttreatment groups. For males with learning problems or conduct disorder, outcomes are poorer than for those without such disorders. Peer use patterns and parental use have a major influence on outcome for males. For females, factors such as self-esteem and anxiety are more important influences on outcomes. The chronicity of a substance use disorder makes relapse an issue that must always be considered when managing patients after treatment, and appropriate assistance from a health professional qualified in substance abuse management should be obtained.

Prevention

Preventing drug use among children and teens requires prevention efforts aimed at the individual, family, school, and community levels. The National Institute on Drug Abuse (NIDA) of the U.S. National Institutes of Health has identified essential principles of successful prevention programs. Programs should enhance protective factors (parent support) and reduce risk factors (poor self-control); should address all forms of drug abuse (legal and illegal); should address the specific type(s) of drug abuse within an identified community; and should be culturally competent to improve effectiveness ( Table 140.9 ). The highest-risk periods for substance use in children and adolescents are during life transitions, such as the move from elementary school to middle school, or from middle school to high school. Prevention programs need to target these emotionally and socially intense times for teens to adequately anticipate potential substance use or abuse. Examples of effective research-based drug abuse prevention programs featuring a variety of strategies are listed on the NIDA website ( www.drugabuse.gov ), and on the Center for Substance Abuse Prevention website ( www.prevention.samhsa.gov ).