Substance Use Disorders in Adolescence Chapter 15 Sandra A. Brown, Kristin Tomlinson, and Jennifer Winward

SUBSTANCE USE DISORDERS IN ADOLESCENCE Most commonly used drug with 20% of 8th graders and 42% of 10th graders report being drunk on at least one occasion in their lifetime (MTF; Johnston, O'Malley, Bachman, & Schulenberg, 2010). Among high school seniors, half report using alcohol in the past 30 days, 31% report being drunk in that time frame, and 28% report 5 or more drinks per occasion during the prior 2 weeks. Rates of daily drinking remain low (3%), highlighting the heavy, episodic nature of youth involvement with alcohol and other substances. Nictoine is the second most commonly used drug. Marijuana is the most commonly used illicit drug.

ABUSE AND DEPENDENCE: CRITERIA AND DIAGNOSTIC ISSUES Indicators of SUDs among adolescents often involve physical, socioemotional, and health changes. Physical dependence, when physiological and psychological adaptations to the substance occur. Tolerance is the need to ingest larger amounts of a substance for an effect once obtained at a lower dose. DSM-IV(2000) Two types of substance use disorders (abuse and dependence) are characterized by a maladaptive pattern of use and symptoms that result in clinical impairment or distress. Abuse typically considered less severe and less chronic than dependence.

HISTORICAL CONTEXT AND ETIOLOGICAL FORMULATIONS Environmental Models Theory of planned behavior (TPB) Attitudes about using substances, perceived social norms of alcohol/drug use, and self-efficacy for coping in potential use situations influence youths’ intentions to use substances (Ajzen & Fishbein, 1980). Social learning theory (SLT) Adolescents develop outcome expectations about the effects of substance use by observing parents, peers, and/or the media, or by learning about the effects of substance use (Akers, 1977).

HISTORICAL CONTEXT AND ETIOLOGICAL FORMULATIONS Problem behavior theory (PBT) A generalist model that considers substance involvement to be one of a number of deviant behaviors that typically co-occur among adolescents (Jessor & Jessor, 1977). Domain model Focus on the interaction of biological, intrapersonal, interpersonal, and sociocultural factors in jointly influencing adolescent substance use behavior (Huba, Wingard, & Bentler, 1980).

HISTORICAL CONTEXT AND ETIOLOGICAL FORMULATIONS Behavioral Genetic, Neurobiological, and Integrated Perspectives Maturation theory A heuristic model of the development of early-onset SUDs. According to this model, deviations in somatic and neurological maturation, along with stressful and adverse environments, predispose children to difficulties in regulating affect and behavior (Tarter et al., 1999). Expectancy theory An alcohol/drug-specific integrative model of youth substance involvement because it considers multiple system levels of potential influence on youth substance use as well as processes through which these systems interact over time in the context of development (Goldman et al., 1991; Goldman, et al., 2010).

HISTORICAL CONTEXT AND ETIOLOGICAL FORMULATIONS Environmental and Genetic Risk Factors Temperament Childhood behavior problems Alcohol and drug expectancies Age of onset Family influences Peers Stress Neurocognitive functioning

HISTORICAL CONTEXT AND ETIOLOGICAL FORMULATIONS Protective Factors Temperamental traits High intelligence Social support Involvement with conventional peers Religiosity Low-risk taking Competence skills Psychological wellness (ALDH2) isoenzyme associated with adverse reactions to alcohol

DEVELOPMENTAL PATHWAYS TO ABUSE AND DEPENDENCE Deviance-prone pathway A parental alcoholism/deviance proneness pathway that operates as a risk factor for behavioral difficulties among offspring ( Zucker et al., 2000). A key feature of this model involves the child’s reduced ability to self- regulate emotional distress and inhibit behaviors, which elevates risk for the development of substance use problems in adolescence. Negative affectivity pathway Deficient regulation of negative affect. This pathway appears to be associated with both exposure to environmental stressors and temperamental negative emotionality. Enhanced reinforcement pathway Some youth are less sensitive to the effects of substances and consequently use substances more frequently and/or in greater quantities (Schuckit et al., 2004). This pathway appears to be genetically influenced and based on physiological response differences to the pharmacological effects of substances.

FUTURE DIRECTIONS FOR PREVENTION Primary and early intervention effects involving peer leaders, motivational enhancement, improved accuracy of perceived social norms, challenges to outcome expectancies, and social practice appear most promising, particularly if including a motivational interviewing approach (Brown, et al., 2008; Winters & Leitten, 2007). There is growing appreciation for considering developmental factors in the timing, content and process of effective interventions. The application of neuroscience findings to interventions.