Resources for the Assessment and Treatment of Substance Use Disorder in Adolescents

Substance Use Disorder (SUD) is understood as the persistent use of substances to the detriment of the individual's livelihood and wellness. SUD can have serious mental, physical, and social ramifications if not properly addressed. Though SUD can develop at any age, it is especially important to address in adolescents, given the rising prevalence of certain substances (e.g. cannabis) in that age group and the poor prognosis associated with early-onset SUD. [1][2] Data from the National Survey on Drug Use and Health show the lifetime use of illicit drugs in people ages 12-17 is 20.9%. [3] The same survey found the rate of Substance Use Disorder in the past year for people ages 12-17 who used illicit drugs or alcohol to be 6.3% in 2020. [3] This paper is intended for clinicians and laypeople to gain a deeper understanding of SUD in adolescents, particularly relating to alcohol, cannabis, nicotine, and opioids. Though alcohol, cannabis, and nicotine are the substances most commonly used by this age demographic nationally, [4] opioid use – and resulting deaths – have been on the rise. According to the Centers for Disease Control and Prevention (CDC), opioids were connected to about 75% of the nearly 92,000 drug deaths in 2020. [5] Beyond significant death rates in the general population, recent spikes in adolescent death rates tied to the synthetic opioid fentanyl – which held a relatively stable death rate from 2010 to 2019 until seeing a 94% increase from 2019 to 2020 and an additional 20% increase to 2021 - warrants inquiry into opioids for this population. [6] Each of these substances can have adverse, long-lasting effects on health if not managed properly, resulting in seriously compromised lifelong well-being. [7]

This paper is intended for clinicians and laypeople to gain a deeper understanding of SUD in adolescents, particularly relating to alcohol, cannabis, nicotine, and opioids. Though alcohol, cannabis, and nicotine are the substances most commonly used by this age demographic nationally, [4] opioid use -and resulting deaths -have been on the rise. According to the Centers for Disease Control and Prevention (CDC), opioids were connected to about 75% of the nearly 92,000 drug deaths in 2020. [5] Beyond significant death rates in the general population, recent spikes in adolescent death rates tied to the synthetic opioid fentanyl -which held a relatively stable death rate from 2010 to 2019 until seeing a 94% increase from 2019 to 2020 and an additional 20% increase to 2021warrants inquiry into opioids for this population. [6] Each of these substances can have adverse, long-lasting effects on health if not managed properly, resulting in seriously compromised lifelong well-being. [7] This article explores SUD prevalence and reviews diagnostic criteria in relation to adolescence, including a synopsis of changes in SUD classification between the DSM-IV and DSM-5 and a discussion of ICD-11 and the Research Domain Criteria (RDoC) as a basis for research related to substance use. Effective assessment and consideration of co-occurring disorders are covered as well. Although the prognosis of SUD varies by an individual's environment and circumstances, a modal developmental course for SUD is discussed. Finally, a curated list of nationally recognized resources including hotlines, treatment locators, informational sites, and support groups is provided, along with tools to compile local resources. By addressing these aspects of adolescent SUD, the research team offers a broader view of its prevalence in the United States, key warning signs and comorbidities, and possible assessments and treatments for adolescents with SUD.

Diagnostic Criteria
While a single established method of classifying and organizing substance use disorders does not exist, two major classification systems are used in psychiatrynamely the DSM-5 and ICD-11. Currently, some researchers are also pursuing other classification approaches to focus more on genetics, molecular physiology, and emerging understanding of neuroscience and behavior. The American Psychiatric Association created and updates the DSM-5 classification system, which is the most well known in the United States and in regions that rely on research done in the United States. The World Health Organization has its own International Classification of Diseases, which covers not only psychiatry, but also all other areas of medicine. It is freely available from their website in several languages, [8] and it is the most widely used system in the world for medicine. In the United States, insurance billing and tracking of illnesses use the ICD. The Research Domain Criteria (RDoC) is an example of an alternative, research-oriented classification approach. This framework has the least immediate clinical application, but an awareness of it may be helpful for those seeking literature on newer scientific research.

Diagnostic and Statistical Manual of Mental Disorders
Substance Use Disorder is defined in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (5th ed.) as "a problematic pattern of substance use leading to clinically significant impairment or distress." [9] The DSM-5, like the International Classification of Diseases (ICD-11), [10] lacks any developmentally-specific or age-specific considerations in the diagnostic criteria specific to adolescent presentation of SUD. [9] The DSM-5 recognizes ten substance classes for SUD, whichinclude: alcohol, cannabis, nicotine, opioids, sed atives, stimulants, inhalants, phencyclidine, other hallucinogens, and other/unknown. [9] To warrant a diagnosis of SUD, at least two of the eleven criteria outlined in the table below must be met in a period of one year. [9] These eleven criteria can be understood as indicators of withdrawal, tolerance, loss of control of usage, prioritization of substance use above most everything, risky or hazardous use, and physical, psychological, and interpersonal consequences of substance use. [9] DSM-5 Criteria for Substance Use Disorder [11] with Examples

DSM-5 Criteria Example
Craving or a strong drive for substance use The DSM-5 outlines specifiers for severity, remission, and treatment environment. The severity specifier is based on the number of DSM-5 criteria that are met. The presence of two or three criteria indicates mild SUD, four to five indicates moderate SUD, and six or more indicates severe SUD. [9] Remission specifiers give context to SUD that has not been active for some length of time. "In early remission" is specified if criteria have not been met in the past three months but have been met at some point in the past 12 months, with the exception of craving, and "in sustained remission" is indicated if the criteria have not been met for the past year. [9] To provide more context around someone who is in treatment, the environment specifier "in a controlled environment" indicates that the person does not have access to any substances because they are currently residing in a restricted environment, such as a rehabilitation center. [9] The DSM-5 classifies Substance-Related and Addictive Disorders, which includes gambling disorder. [12] Moreover, the DSM-5 consolidated substance abuse and substance dependence, which were separate in the DSM-IV, into one set of criteria for a diagnosis of SUD. [13] In addition to these structural changes, criterialevel changes were made. The DSM-5 added the criterion of craving and removed the DSM-IV criterion of recurrent substance-related legal problems. [12] [13] These changes came from an analysis of 39 studies totalling over 200,000 subjects which plotted criterion severity against how well a criterion discriminates between subjects of high or low severity. [13] Ultimately, a pattern emerged such that substance abuse and substance dependence criteria were related to severity, with the exception of the legal issues criterion and the addition of craving criterion. [13] Further, the legal issues criterion displayed low endorsement and poor discrimination. [12] The addition of a craving criterion also helped to improve cross-classification system continuity, as this criterion was already used in the ICD-10. [12] Additionally, a threshold of two criteria to receive a diagnosis was set given the urgency of early intervention for successful treatment outcomes. [13] Given findings that meeting an increasing number of SUD criteria was associated with increasing consequences of the disorder, current nosologies designate severity as mild, moderate, or severe based on the total count of criteria present. [13] A study estimating the impact of diagnostic criteria changes on diagnoses of SUD found that using DSM-IV criteria tends to underestimate SUD prevalence compared to DSM-5 criteria. [12] It is possible that the DSM-5's addition of "craving" as a criterion may have increased the likelihood of passing the threshold to meet a Substance Use Disorder for certain substances (e.g., alcohol, hallucinogens, prescription painkillers), identifying cases which otherwise wouldn't have been captured as having a Substance Use Disorder. [12]

International Classification of Diseases
The International Classification of Diseases (ICD) is a global diagnostic system under the World Health Organization oriented around clinical use and scientific validity used to categorize and diagnose disorders. [14] The ICD-11 first segments these disorders by substance. [15] Specified substances include all substances recognized by the DSM-5 and additional substances of synthetic cannabinoids, synthetic cathinones (bath salts), MDMA, dissociative drugs, and non-psychoactive substances. [16] After the substance itself is specified, the ICD-11 categorizes the disorder as either harmful use or dependence. [15] Harmful use could constitute physical or mental harm to oneself (e.g., injuries sustained from car crash while driving high) or to another (e.g., PTSD developed by victim of druginduced rage). [15] Dependence, the more severe diagnosis, is characterized primarily by impaired control over substance use and a strong drive to use the substance. [15] Finally, a harmful use disorder is categorized as episodic or continuous. To qualify as episodic use, the substance use and symptoms must be present over the past year. [17] In cases of heavy use, with near-daily use and symptoms, the disorder is classified as continuous use. [16] The following table provides examples of ICD-11 diagnoses of harmful use for alcohol (episodic) and cannabis (continuous), as well as ICD-11 diagnoses of dependence for nicotine (current) and opioid (current) use. Opioid dependence, current use Opioid dependence, with use of an opioid within the past month. Diagnosis of ICD-11 opioid dependence would require impaired control over opioid use (e.g., try to limit use to 1 pill per day, but repeatedly used more than planned due to subjective compulsion to use) and a strong drive to use opiate (e.g., craving). Nicotine dependence, current use Current nicotine dependence with nicotine use within the past month. Diagnosis of ICD-11 nicotine dependence would require impaired control over nicotine use (e.g., difficulty quitting nicotine use, at least one serious unsuccessful attempt to stop) and a strong drive to use nicotine (e.g., craving). Harmful pattern of use of alcohol, episodic A pattern of episodic or intermittent alcohol use that has caused damage to a person's physical or mental health or has resulted in behavior leading to harm to the health of others. The pattern of episodic alcohol use is evident over a period of at least 12 months.
Harmful pattern of use of cannabis, continuous A pattern of continuous (i.e., daily, almost daily) cannabis use that has caused damage to a person's physical or mental health or has resulted in behavior leading to harm to the health of others. The pattern of continuous cannabis use is evident over a period of at least one month.
A major strength of the ICD-11 is the ease of interfacing with a diverse range of clinical and healthcare settings. The ICD-11 is widely accepted by hospitals, practitioners, and insurance companies both in the US and abroad for physical and mental health disorders. [18] Aside from the high-level benefit of ease of use, the differentiation of disorder by substance class allows for specification in substance-specific medical interventions and treatment of withdrawal symptoms. Moreover, segmenting diagnoses as harmful use or dependence can provide an opportunity to tailor level of intervention to pattern of use, allowing for early intervention at a crucial stage of harmful use or more intensive levels of intervention for dependence. [15] However, the ICD-11, similar to the DSM-5, lacks any adolescent-specific criteria or diagnoses for SUDs.

Research Domain Criteria
Developed by the National Institute of Mental Health in 2009 for research rather than clinical use, the Research Domain Criteria (RDoC) is a system rooted in neuroscience to understand classification of mental disorders from a dimensional perspective. [19] [20] Although traditional diagnostic systems focus on symptoms and clinical presentation, the RDoC pays special attention to biological mechanisms on multiple levels of analysis. [19] [21] The RDoC outlines major transdiagnostic neurobiological and observable behavior domains. [19] For each domain, RDoC organizes a matrix of operational definitions, with the goal of understanding links between different levels of analysis extending from genes to molecules, cells, circuits, and physiological systems, up to observable behaviors and subjective experiences usually assessed by self-report. RDoC also seeks to organize operational definitions of different domains at the level of animal models and laboratory tasks for use with humans (which it refers to as "paradigms").
Regarding Substance Use Disorder, at least three of these domains are clearly implicated: cognitive systems, positive valence, and negative valence. [22] [23] The cognitive systems domain covers executive functioning and preoccupation with obtaining or using substances, while the positive valence domain includes reward pathways, and the negative valence domain involves general negative emotional and stress responses. [22] These three domains meet in the model of addiction such that individuals who are more sensitive to rewards are at risk of initial substance use, which can escalate to heavier use through the interaction of cognitive systems and negative valence systems. For example, according to the "selfmedication" hypothesis, chronic heavy substance use may serve to reduce negative valence subjective states, such as anxiety; heavy substance use might be used to prevent or relieve withdrawal, though it is important to note that negative affect might be a symptom of withdrawal. [24] [25] The RDoC was developed as a tool for researching domains and functions based on neurobiological phenomena, but it has been proposed to be adapted for assessment of Substance Use Disorder. [25] Although intended to be transdiagnostic, the original formulations did not specifically have addictive disorders in mind, and it is not clear whether RDoC domains currently provide comprehensive coverage of the constructs and systems important to understanding substance use. [25] The National Institute on Alcohol Abuse and Alcoholism (NIAAA) is exploring the development of an "Alcohol Addiction RDoC" (AARDoC) to address some of these concerns. [25] The Addictions Neuroclinical Assessment (ANA) grew out of this initiative. [22] . The ANA assesses the RDoC domains relevant to addiction (cognitive -specifically focused on executive function, positive valence -specifically incentive salience, and negative valence -specifically negative affect as a part of withdrawal) through an amalgam of self-report questionnaires, various behavioral tasks, and neuroimaging (including fMRI) which amounts to an approximately 10 hour comprehensive battery. [22] Though the ANA is a recent development, it has shown promising validity in measuring negative valence in men and women seeking treatment for Alcohol Use Disorder. [26] Support for aberrant brain functioning at each stage of the ANA's proposed addiction cycle (i.e., binge/intoxication, withdrawals/negative affect, preoccupation/anticipation) has been identified. [27] Future research will test if the ANA can effectively specify treatment based on measurements of AARDoC domains. [26] Currently, however, the RDoC remains predominantly used in research settings rather than clinical settings. [19] [28]  . [29] Usage varies by substance and considering both pointin-time use statistics and trend over the past decade provides context to prevalence. Alcohol remains the most prevalent for annual use at 30.2% despite the downward trend over the past decade. [29] Any illicit drug use lands at 19.9% and has seen a relatively flat trend line in the past 10 years. [29] At 17.9%, marijuana has the highest annual prevalence among illicit drugs surveyed and use has remained relatively consistent over the last decade. [29] 30-day cigarette use has decreased every year in the last decade and sits at 2.3%. [29] Across all of these substances, adolescent usage has decreased from 2020 to 2021. [29] Future studies examining data from the coming years (e.g., 2022-2026) may to show whether this was a temporary reduction or a step function lowering the plateau of prevalence to a "new normal". Additionally, considering usage by grade level allows for another understanding of prevalence. For all of these substances, prevalence increased as grade level increased. [29] This suggests that at least for adolescents' grades 8 to 12, as adolescents get older, substance use becomes more prevalent.
While cigarette usage is at an all-time low of 2.3%, nicotine may be used in several forms and thus requires further examination. Nicotine use prevalence was reported for 8th, 10th, and 12th graders combined across different modalities in Monitoring the Future. In 2021, 30-day prevalence for nicotine use was highest for nicotine vaping (13.3%), followed by cigarettes (2.3%), smokeless tobacco (1.8%), large cigars (1.5%), flavored little cigars (1.5%), regular little cigars (1.3%), and finally tobacco using hookah (0.9%). [29] Examination of nicotine use prevalence should continue to account for both common and emerging forms.
Opioid use similarly can be segmented into several categories. Specifically considering past year opioid misuse (i.e., use of a medication such as opiates in any way that a doctor did not direct) among 12-17 year olds, the prevalence is 2.8% in 2018, down from 3.9% in 2015. [30] Substance use and SUD prevalence differs significantly across gender, race, ethnicity, and sexual orientation. In early adolescence, females have higher rates of substance use than males. [31] However, by midadolescence and early adulthood, males generally surpass females in substance use. [32] Differences by race and ethnicity also emerge, such that Hispanics have the highest rate of substance use in early adolescence, but Caucasians had the highest rate by mid-adolescence. [32] Regarding sexual orientation, a meta-analysis found that sexual minority adolescents have a higher prevalence of SUD than heterosexual adolescents, such that on average, the odds of SUD for a sexual minority youth were 190% more than their heterosexual counterpart. [33] While understanding prevalence of substance use is important, substance use does not necessarily indicate substance use disorder. Thus, substance use disorder must be considered separately.

Substance Use Disorder Prevalence
The Substance Abuse and Mental Health Services Administration's National Survey on Drug Use and Health (NSDUH) provides another national source of information on the prevalence of adolescent substance use, and unlike Monitoring the Future, assesses substance use disorder. Analyzing the prevalence of specific SUDs over a 5-year trend can help to understand patterns. Since 2020 data reflects an updated methodology that is not comparable to prior years, 2020 is considered independently and 2015-2019 can be reviewed to understand trend over time. [3]

National Household Survey on Drug Use and Health: Percentages of 12-17-Year-Olds with SUD for Specific
Substances [ In 2020, the National Survey on Drug Use and Health (NSDUH) found that 6.3% of adolescents in the sample population between the ages of 12-17 had a SUD in the past year for either illicit drugs or alcohol. [3] Considering specific SUDs for alcohol, cannabis, and opioids, cannabis consistently sees the highest prevalence of SUD (4.1%), followed by Alcohol Use Disorder (AUD) (2.8%), and opioids (0.3%). [3] Comparing 2015 to 2019, Cannabis Use Disorder was the only SUD to slightly increase in prevalence, while any substance, alcohol, and opioids decreased to varying degrees. [3] Beyond the baseline rate of SUD in the general population, it is helpful to know SUD prevalence across diverse settings. A study from 2001 in California assessed past year prevalence rates of SUD in adolescents across five clinical settings. In formal alcohol and drug sectors of care, 42.6% of participants reported SUD in the past year. [38] Juvenile justice settings had a 36.9% prevalence rate. [38] In mental health care settings, prevalence was 22.9% . [38] Public school services for adolescents with severe emotional disturbance had a prevalence rate of 16.0%. [38] Child welfare settings had a prevalence rate of 11.0%. [38] A review found that homeless adolescents were at a particularly elevated risk of SUD (i.e., ranging from 44-86% of substance-using homeless youth). [39] Each of these settings has a rate of SUD higher than we find in the general population of adolescents age 12-17, which highlights the need to consider situational context when understanding prevalence of SUD.

Comorbid Disorders
Within SUD, Rates of Other Disorders Among those diagnosed with substance use disorder, certain comorbidities are more common. Approximately 60% of adolescents in communitybased SUD treatment satisfy diagnostic criteria for one or more co-occurring psychological disorders. [40] [41] A review found that the most common comorbidity for adolescents with SUD was a category of disruptive behavior disorders including Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD). The median prevalence of co-occurring ODD and CD was 46.0%. [40] There is some evidence for a cyclical relationship between substance use and behaviors associated with conduct disorders, such that one condition increases the other and vice versa, leading to increasing severity of both conditions over time. [42] Depression was also common, with a median comorbidity rate of 18.8%. [40] Comorbid Attention Deficit Hyperactivity Disorder (ADHD) had a prevalence of about 12.3%, however, it is important to note that this may be partially explained by the high degree of correlation between ADHD and ODD/CD. [42] Another review found that among adolescents with SUD, prevalence of co-occurring conduct problems was 69%, anxiety was 38%, and depression was 30%. [43] SUD is also associated with suicide in adolescents. [42] Teenagers with SUD are about three times more likely to attempt suicide than their counterparts who do not use substances. [42] The issue of suicide is particularly relevant to adolescents, because it is the third leading cause of death in Americans ages 10 to 19. [42]  Moreover, some disorders, particularly anxiety and behavior disorders, typically have higher rates of a SUD comorbidity. One study found that prevalence of substance use among adolescents is highest for those with prior anxiety disorders (e.g., Generalized Anxiety Disorder, Panic Disorder, Post-Traumatic Stress Disorder) and behavior disorders (e.g., ADHD, CD, ODD). [44] Having any prior mental health disorder was found to significantly increase the risk of starting alcohol use and escalating alcohol use, and similar associations were found between prior mental health disorders and illicit drug use. [44] In fact, 20% of adolescents with prior anxiety disorders experienced drug-related problems, and 17.3% of adolescents with prior anxiety disorders experienced alcohol-related problems. [44] For adolescents with prior behavioral disorders, 24% experienced drug-related problems and 15.6% experienced alcohol-related problems. [44]

Rates in Clinical Settings
Among different settings, comorbidities are typically more common in clinical environments for the treatment of SUD. [45] Co-occurring mental health problems range in prevalence from 64-88% among adolescents in SUD treatment settings. [46] In 2018, 65.7% of adolescents with co-occurring SUD and major depressive episodes received some type of mental health services or substance use services. [47] 59.5% received mental health services only, 5.4% received both mental health and substance use services, and 0.8% received substance use services only. [47]
Considering motives for substance use in adolescents, adolescence is a time of intense change within the individual and their social networks and these processes and interactions increase both opportunities and motives for use and experimentation. [48] [49] Regarding prevalence, substance use and SUD prevalence rises throughout adolescence and reaches a peak in early adulthood. [1] Beyond prevalence, the manifestation of substance use disorder depends on developmental stage, as substance use among adolescents manifests differently than among adults. Moreover, the nuances of adolescent substance use and risks are shaped by legal and logistical barriers to obtaining substances which can increase risk of binge use, increased sensitivity to peer influence, and stilldeveloping brains that make substance use at this age particularly dangerous. [42] For example, because a minor cannot purchase alcohol, adolescents drink less frequently than adults yet are more likely to engage in binge drinking with peers, who may provide access to alcohol. [42] Binge drinking is a high-risk activity, as it may lead to neurological damage or accidental injury/death. [42][50] [51] Onset and Referral to Treatment Age of onset of substance use has associations with prognosis. Early onset substance use, defined as use prior to age 14-15 for alcohol and age 16 for cannabis, is associated with a higher risk of consistent and longterm SUD. [2] Early substance use progresses to either an adolescent-limited course or a chronic course with high risk for SUD throughout adulthood. [2][52] Those with comorbid disorders and certain temperament characteristics, such as behavioral disinhibition, are at higher risk for developing a chronic course of SUD. [2] Once diagnosed, treatment for substance use disorder also has specific nuances for adolescents. Adolescents are often referred to substance use treatment by external sources, such as parents or family members, their school, or the juvenile justice system, rather than self-referring. In 2015, for adolescents aged 12-17, referrals to publicly-funded substance use treatment by the court/criminal justice system represented 43% of adolescent admissions, while individual referrals comprised 20%, and school referrals accounted for 13%. [53] Furthermore, not all adolescents receive treatment for SUD. According to the NSDUH, 0.5% of adolescents aged 12-17 reported that they received treatment for substance use within the last year (2019), [54] representing a fraction of those meeting criteria for Substance Use Disorder.

Treatment Outcomes and Relapse
Treatment outcomes vary for adolescents, though there are several factors that influence and/or are correlated with positive outcomes. Factors associated with better treatment outcomes and positive prognosis include completion of treatment, high motivation to abstain, low substance use when commencing treatment (i.e., milder presentation), and more social support from non-using family and friends. [2][55] Course and outcome are also influenced by factors such as cooccurring disorders, ethnic background, and gender. [56] There are also various predictors of poor adolescent SUD outcomes. A comprehensive review of the role of personality traits found that impulsivity is a key predictor of negative outcomes in individuals with Substance Use Disorder. [57] Substance dependence during adolescence also predicts poor prognosis. [58] Moreover, initiating substance use early in life is a predictor of increased use of multiple substances (e.g., alcohol, cannabis, opiates). [59] Predictors of substance use have been demonstrated to differ across race as well, where lower distress tolerance was significantly related to higher past year alcohol use among Caucasian adolescents but had no significant relationship among African-American adolescents. [60] Relapse rates are high for adolescents who have received outpatient treatment for SUD; one study found a six-month relapse rate of 66% and a median time to relapse of 54 days without any significant difference by demographic factors or comorbid disorders. [61] A large review showed six-month relapse rates at 62% and one-year relapse rates at 68%. [55] Reported reasons for relapse differ between adolescents and adults; adolescents tend to attribute relapse to social situations and peer use, while adults often attribute relapse to coping with negative emotions. [2] However, relapse for cigarette use is an exception -teens tend to attribute cigarette use to a compulsion to use rather than peer pressure. [2] Recovery is not guaranteed with any initial intervention, and often those with SUD will require numerous attempts to overcome SUD before longterm success is achieved. [62] Evidence-Based Assessment This section is intended to provide an assessment model for clinicians who may not be specialized in substance use disorder. For clinicians who are specialized in Substance Use Disorder, this resource kit may be more applicable. While assessments are often used as screeners or diagnostic tools, they can also be helpful tools throughout treatment. The integrative Evidence-Based Assessment (EBA) model is a framework for using clinical psychological assessments at all stages of clinical care: prediction, prescription, and process. [63] With "prediction" of adolescent Substance Use Disorder, consistent use of brief screeners for substance use in mental health and medical care settings can catch substance use that would otherwise go undetected, allowing for early intervention and treatment implementation. [64][ 65] In the absence of these screeners, clinical judgement alone underestimates adolescent substance use and often doesn't identify the problem until late-stage behavioral issues become apparent. [66] With "prescription," assessments can help a clinician determine the best treatment plan for an adolescent with a SUD, considering the individual holistically. In this vein, assessments can help the clinician determine the substance use severity, motivation for the substance use [67] and the adolescent's readiness for change, [68] while also considering caretaker reports, toxicology testing, and external school, medical, and legal reports. [65] After developing a treatment plan in collaboration with the adolescent based on the comprehensive evaluation, assessments should be continuously used throughout the treatment to gauge the "process," allowing for the treatment plan to adapt as needs change and for outcome goals to be measured. [63] There are many options for evidence-based screeners for initial assessment of adolescent substance use. These validated screeners assess substance use along a continuum based on frequency and intensity of use. [66] Screening to Brief Intervention (S2BI) asks about the frequency of use in the past year of eight types of substances (i.e., tobacco, alcohol, cannabis, illegal drugs like cocaine or ecstasy, non-prescribed prescription drugs, misuse of OTC medication, inhalants, herbs or synthetic drugs) with six frequency responses ranging from "never" to "daily. " [69] The Brief Screener for Tobacco, Alcohol, and Other Drugs (BSTAD) asks about the individual's and their friends' substance use in the past year, along with one's individual frequency of use in the past 30, 90, and 365 days. [70] The Global Appraisal of Individual Needs Short Screener (GAIN-SS) is a broader assessment, looking at four sub-scales for internalizing disorders, externalizing disorders, Substance Use Disorder, and crime/violence. This can be helpful in determining comorbid disorders in addition to substance use issues. The substance use items focus on the frequency of usage, priorities of substance use, and problems related to substance use. [71] The CRAFFT screener is an acronym for Car, Relax, Alone, Friends/Family, Forget, Trouble. This screener asks questions about frequency of substance use and identifies problems associated with substance use related to the dimensions represented by the acronym. [72] [73] Alcohol Use Disorders Identification Test (AUDIT) specifically screens for hazardous drinking, asking questions about frequency of use, alcohol dependence, and alcohol-related problems. While the screener was created for adults, research supports its use for adolescents ages 14 to 18 as well. [74] The Personal Experience Screening Questionnaire -Brief (PESQ-Brief) screens for adolescent substance abuse and includes 18 questions spanning use and relevant behavior to determine if further assessment is recommended. [75] If substance use is indicated in a brief screener, further assessment can help a clinician gain insight on the severity of substance use, along with other individual and environmental characteristics that can aid and inform the optimal treatment plan. The Problem Oriented Screening Instrument for Teenagers (POSIT) is a longer screener with 139 items that explores an adolescent's current functioning, focusing on substance use, physical and mental health, family and peer relations, educational and vocational status, social skills, recreational activities, and aggressive/criminal behavior. [76] The Problem Oriented Screening Instrument for Parents (POSIP) is the parental version of the POSIT, asking similar questions from the caregiver's perspective. [76] The Teen Addiction Severity Index (T-ASI) is a semistructured interview that assesses the adolescent's functioning across seven domains: substance use, school, vocation, family, legal status, peer relationships, and mental health status. Each domain is rated from one to five in terms of both perceptions of impairment and need for treatment. [77] The Global Appraisal of Individual Needs Initial (GAIN-I) is a semistructured diagnostic interview that can help diagnose Substance Use Disorder and inform treatment placement and planning along with outcome monitoring. The GAIN-I focuses on the same four subscales as the GAIN-SS: substance problems, internal mental distress, behavior complexity, and crime/violence. [78] If a clinician specifically wants to know more about an adolescent's alcohol-related problem behavior, The Rutgers Alcohol Problems Index (RAPI) is an 18 item questionnaire that asks about the frequency of issues like going to school drunk, avoiding responsibilities, and blacking out. [79] Similarly, the 23 item Marijuana Adolescent Problem Inventory (MAPI) assesses problem behavior related specifically to cannabis use. [80] Figure 7: The Readiness Ruler is a tool to assess readiness for change. Link to original study. Public domain.
In addition to assessing severity of use and substance use-related problems in functioning, learning about the adolescent's context of substance use, motives for substance use, and readiness to change their behavior can help inform treatment planning and assess ongoing treatment. [65] The Time Line Follow-Back (TLFB) is a calendar-based method of reporting substance use in the past month. [81] This assessment not only gives information on the frequency and severity of use but can also highlight the contexts in which the adolescent tends to use the substance and illuminate patterns of their use. [82][83] A demo of an online version of the TLFB with scripts for clinicians to use to make their own version can be found here. The Drinking Motives Questionnaire Revised (DMQ-R) [84] and Comprehensive Marijuana Motives Questionnaire (CMMQ) [85] assess the adolescent's reasons for substance use. The DMQ-R looks at four main motives for alcohol use: drinking to be social, drinking to cope, drinking to enhance positive emotions, and drinking to conform with peers. [84] The CMMQ looks at 12 main motives for cannabis use: enjoyment, conformity, coping, experimentation, boredom, alcohol, celebration, altered perception, social anxiety, relative low risk (e.g., "because it is safer than drinking alcohol"), sleep/rest, and availability (e.g., "because it is there"). [85] In both measures, "using to cope" was associated with more negative consequences, as was "using to sleep/rest" for the CMMQ. [84] [85] To assess motivation to change substance use behavior at the onset or during treatment, clinicians can use the Contemplation Ladder [86] or the Readiness Ruler. [87] The Contemplation Ladder has 11 "rungs" that range from statements of no desire to change, to ambivalence or taking action. [86] [88] The Readiness Ruler is a visual scale from one to ten with similar markers along the continuum of change. [87] [89] These tools can help the clinician gauge the adolescent's feelings about treatment and desire or resistance to changing their substance use.
In addition to self-report and interview assessments, toxicological tests of urine, blood, or hair are recommended to detect substance use at the onset of and throughout treatment. [58] However, a negative test does not necessarily mean the adolescent is not using drugs, as drugs only temporarily remain in urine and results can vary based on the type of substance and frequency of use. [58] While some studies have found self-report measures to be highly correlated with urine tests, [90] [91] others have found self-report measures to be inconsistent with urine tests, with some adolescents who report substance use having negative urinalysis and other adolescents who deny substance use having positive urinalysis. [92][93] Therefore, the results from multiple types of assessments should be considered by the clinician. Adolescents may under-report or deny use in a clinical setting due to fear of negative ramifications like legal repercussions or parental consequences. [93] In addition to supplementing adolescent self-report by cross-referencing with parental-reports and biological testing, validity of adolescent self-report can be improved by building rapport with motivational interviewing techniques [94] and by discussing confidentiality guidelines and limitations prior to assessment. [64] Evidence-Based Treatment Determining the optimal treatment for adolescent substance use disorder requires careful consideration of multiple factors. According to the American Society of Addiction Medicine (ASAM) criteria, [95] clinicians should consider the patient on six dimensions to approach their treatment planning from a holistic perspective. These include the individual's addiction history, severity, withdrawal potential, any physical health/medical conditions (e.g., STIs, HIV, pain), as well as the individual's mental health, readiness to change, risk of relapse, and the recovery situation/support available to the individual. [95] With these factors in mind, the clinician can determine the best intensity of treatment for the patient on the continuum of care options, ranging from brief intervention, to outpatient services, intensive outpatient services, residential/inpatient services, or medically managed intensive inpatient services. [95] Adolescents should be treated in the least restrictive care setting that still provides necessary care and a safe environment. [95] While more intensive residential programs may be needed in more serious cases, outpatient therapy is the most common treatment for adolescents and can foster generalization of treatment gains. [58] Additionally, the Screening, Brief Intervention, and Referral to Treatment (SBIRT) is another resource available which addresses larger, systemic, and intersecting causes and situations which might contribute to adolescent SUD. [96] [97] The SBIRT works with the current healthcare structure, including primary care centers and providers, hospital and trauma centers, and other public-facing organizations to create an intervention and provide timely treatment for those at risk or for those who already suffer from SUD. [96] [97] It does so by rapidly determining the amount of substance use to determine proper treatment, working to heighten knowledge of substance use and what behavioral change is required for sustained change, and connecting the individual with adequate treatment referrals so the individual can continue receiving needed support and care. [96] [97] There is not a "one-size-fits-all" treatment for adolescent substance use disorder, and the best treatment varies based upon the type of substance and the adolescent's particular needs and problems. These needs will likely change over time and treatment should continually be assessed and adapted through a continuing care approach. [98] Treatments can be considered across four categories: individual therapy, family therapy, pharmacotherapy, and multisystemic/multidimensional therapy.

Individual Therapy
Individual therapy can be offered across multiple levels of care. The least intensive of the ASAM criteria levels of care is early intervention. [95] This is often implemented through a brief intervention delivered by a primary care provider or other medical professional. This brief intervention is a short conversation between the provider and patient that is tailored to the severity of substance use that the patient disclosed on a screener assessment. The focus should be on preventing, reducing, or stopping substance use. The provider should give clear advice to abstain from the substance, information on negative effects of usage, and discuss a plan to stop usage that emphasizes individual strengths and positive behaviors of the patient that will help them abstain. [66] Specific training guidelines by the American Academy of Pediatrics for primary care providers on how to deliver a brief intervention for adolescent substance use can be found here. For adolescents who need more than a brief intervention, the next level of care according to ASAM criteria is outpatient therapy. [95] This treatment may consist of many different elements and forms of therapy in order to address the multiple needs of the adolescent around their substance usage including family therapy, individual behavioral therapy, support groups, medication, and legal services. Given high comorbidity rates among adolescents with SUD, co-occurring disorders should be screened in all SUD treatment settings. Along with SUD, these co-occurring disorders must be appropriately addressed with evidence-based methods in order for the adolescent to return to developmentally-appropriate functioning. [58] Throughout treatment, it is beneficial for treatment providers to continually assess substance use as relapse is common and recovery is a long-term process. [98] Abstinence from drug use is strongly recommended, with a focus on motivation, family engagement and support, skills-building and relapse prevention, cooccurring disorder treatment, multi-system intervention, and completion of treatment and followup. [58] [55] Ensuring that services that are developmentally, culturally, and gender-appropriate is also necessary when determining treatment for adolescent substance use. [98] This means that adolescents should not be treated at adult-based programs and providers should work to be culturally responsive. [99] [100] In general, the most efficacious therapies for adolescent Substance Use Disorder are cognitive behavioral therapy (individual, group, and family) and motivational enhancement treatment with CBT, along with family-based ecological treatment (discussed below). [98] Cognitive Behavioral Therapy helps adolescents anticipate their problems and enhance their self-control. CBT helps individuals recognize cravings and situations that are high-risk for their substance use and build adaptive coping skills and strategies to avoid or manage cravings. Cognitive Behavioral Therapy (CBT) with Motivational Interviewing (MI) has been shown to reduce issues associated with comorbid internalizing disorders and SUD. [46] Developing adolescent buy-in to therapy is crucial to treatment completion and relapse prevention, especially since adolescents rarely selfrefer and instead are typically pressured or forced into treatment by a caregiver, the school system, or the juvenile justice system. [101] Motivational Enhancement Treatment can help drive treatment compliance and retention in adolescents with SUD by helping individuals increase their motivation for recovery and build a plan for change. [58][55] [98] In addition to these therapies, twelve-step groups such as AA or NA have been shown to be beneficial as supplemental or continuing treatment, with the caveat of locating groups with age-similar members to increase the adolescent's engagement and identification with other members at the meeting. [58] [102] Similarly, building peer support systems of non-substance using peers can be a driver of sustained behavior change and help prevent relapse. [58] [55] The NIH has suggestions on how to find adolescent treatment support groups here, and this toolbox from University of Massachusetts Medical School helps practitioners effectively employ peer support programs.

Family Therapy
Family-Based Ecological Treatment is one of the most effective therapies for adolescent SUD. [98] Family therapy is important as family relationships and contexts are important risk factors for adolescent SUD and families can institute important environmental changes. [58] There are many forms of evidence-based family therapy for adolescent substance use disorder. Family Behavior Therapy focuses on the substance use issues along with other simultaneous problems including conduct disorders, depression, mistreatment (e.g., physical abuse, sexual abuse, neglect), and family conflict. [103] [98] The therapist meets with the adolescent and at least one caregiver to help them create behavioral goals for substance abstinence and build new skills to cope with co-occurring issues. The therapy also uses contingency management and allows the patients to contribute to the treatment planning. [103] [98] Brief Strategic Family Therapy (BSFT) focuses on identifying and changing family patterns that are thought to continue or worsen adolescent substance use and conduct problems. [62] The approach of BSFT is flexible and can be adapted to many settings and modalities of treatment from outpatient therapy to being a part of a residential program or continuing care plan. [62][98] Currently, over-the-counter nicotine chewing gum, lozenges, and skin patches are the only FDA approved medications for adolescent substance users and should only be used with physician consultation. [98] Recent research suggests that buprenorphine, a prescription medication for treating opioid addiction, may be effective for adolescents age 16 and older, but the medication has not yet been approved by the FDA for adolescents under the age of 16. [104][105] [106] Other medications for treating opioid, nicotine, and alcohol Substance Use Disorder are currently being researched to determine their safety for adolescent populations. [98] Multisystemic and Multidimensional Therapy Other forms of therapy are more comprehensive and community-based, addressing the influence of school, peers, and community in the treatment. [98] Since family, school, and peer systems significantly shape adolescent behavior and exert considerable structure and control on their lives, aligning these systems with recovery-focused goals can be highly influential to decreasing instances of relapse and to address and overcome trauma that may be a root cause of the SUD. [32] One of these types of comprehensive Substance Use Disorder treatments that works with the adolescent and their family is Multisystemic Therapy (MST). [107] MST is especially helpful for adolescents who display antisocial behavior along with their substance use. This intensive treatment occurs in natural environments in the patient's home, school, and/or community and addresses individual factors, family conflict, peer influence, school issues, and neighborhood cultural influences on drug use. [98] MST has high retention rates and has been found to significantly reduce substance use for at least six months after treatment. [108][109] [110] When considering comorbidities, best clinical treatment outcomes are associated with parallel use of both mental health services and substance use services, targeting both the comorbid psychiatric disorder and substance use issues. [46] Multisystemic therapy (MST) works well with treating comorbid conduct disorders (CD) and SUD, showing long-term beneficial effects on adolescents. [46] Other therapies that show positive benefits for CD and SUD in terms of reducing delinquent behavior include Multidimensional Family Therapy (MDFT) and the Adolescent Community Reinforcement Approach (A-CRA). [46] Multidimensional Family Therapy (MDFT) considers adolescent drug use through the lens of multiple interconnected networks of the individual, family, peer group, and community. The therapist works with the individual to build important developmental skills for problem solving, decision making, and communication along with vocational skills. MDFT works to increase desirable behavior and decrease drug use and other problem behaviors across many different settings with multiple strategies. Parallel sessions with the caregiver focus on examining parenting styles and negotiating developmentally appropriate levels of control and influence. [98][111] [112] Resources The goal of this section is to illustrate a range of informational and clinical resources, using internet searches as the point of entry given smartphone and internet searches are a common way that the general public seeks information and treatment options. Reliance on internet searches has increased, and so using effective search strategies becomes necessary. Use of targeted search terms, search engine best practices, and related key words helps to ensure that specificity can be achieved in search results, especially as services may be divided between general health, mental health, substance use, and more. Additionally, the high level of stigma around the topic of substance use makes the privacy of online searches particularly well-suited for initial information gathering. [113] Online search is also a primary strategy for health professionals. [114][115] [116] The value of online search for professionals is accentuated with regard to substance use due to the fragmentation of services combined with the value of integrated care models for addressing the multiple needs of many people. [117] Online searches for resources also are a key component of foregrounding information gathering as providers start their practices, relocate to a new area, or seek to support patients who themselves are relocating or inquiring about resources for friends and family in other geographic locations.
This section combines two approaches. The first is to focus on high quality and nationally accessible sources, such as content from federal agencies and national hotlines. The second is to seek local resources along a continuum of care, which is crucial to find and identify services such as individual counseling, support groups, and intensive-outpatient, partial hospital, inpatient, and residential programs. The full continuum of care services as outlined by the American Society of Addiction Medicine include the following levels: early intervention, outpatient treatment, intensive outpatient treatment and partial hospitalization, clinically managed residential/inpatient services, and clinically managed intensive inpatient services. [95] It is important to note that all levels may not be available at all geographic locations.
When considering care and treatment options, as well as resources, it is important to consider the level of care needed and which places provide it. Furthermore, cost, including degree of insurance coverage, location of the treatment center relative to ability to access, and qualifications to receive the specific treatment (which can be restricted based on age, substance type, length of treatment, etc.). Researching and carefully comparing options which consider these factors among others can help to optimize the care and treatment received.
In terms of search strategies for finding substance use resources and treatment centers, using quotation marks ("") around phrases and words that you want to keep together in search results is helpful to ensuring that the information you want included is maintained in your search results. [118] For example, adding your city and state at the end of the search term and within quotations would be a helpful practice. Additional search tips, like using a tilde (~) to search for words and synonyms, typing "related" in the URL field to find complementary websites, and hashtags (#), among other keyboard shortcuts can also prove useful. [119] [120] Always beware of search results which might not be reputable, potentially including advertisements that appear at the top of the search results. Sources that are not reputable may lack appropriate care (e.g., lack evidence-based treatment or properly licensed/certified providers).

National Resources
In the event of a life-threatening emergency, immediately call 911, which is available throughout the United States and Canada. Similar emergency services are available in many other countries. In the US, an individual in crisis looking for immediate support may also call or text the 988 Suicide & Crisis Lifeline at 988 or chat online at 988 Lifeline to talk to a trained operator anytime in a free, confidential setting. [121] The US transitioned to this 3 digit number in July 2022, though the original 10 digit number, 1-800-273-8255, will also remain in service and route to 988. [122]  National resources are available to provide information hubs on SUD for adolescents and their support systems. The Substance Abuse and Mental Health Services Administration's (SAMHSA) website is an easily accessible resource that provides confidential and free information services for individuals and family members facing substance use disorder. Moreover, SAMHSA National Helpline is available 24/7 at 1-800-662-4357. SAMHSA's national treatment locator can also be used as a search engine for finding reputable care and further treatment.
Furthermore, the Society for Adolescent Health and Medicine (SAHM) offers a plethora of resources for young adults to find resources pertaining to SUD. From the Partnership for Drug-Free Kids, a resource aimed at assisting families and individuals with SUD, to the Kelty Mental Health Resource Centre, which offers information on SUD and comorbid disorders, there are many ways to find help at the national level. Likewise, NIDA for Teens is a website covering national research findings related to SUD.
National resources are available to locate treatment options for adolescents with SUD. Higher Ed allows for drug rehab searches by state or city and details service options, level of care, treatment type, payment type, clients served, and contact information for each resource. [123] The SAMHSA website also provides information on thousands of state-licensed providers who specialize in treating Substance Use Disorder, addiction, and mental illness. [ For those in recovery, national support groups might be a beneficial way to further one's rehabilitation journey; Alcohol Anonymous and Narcotics Anonymous offer support to adolescents and young adults, and meetings nearby can be found on their respective websites. SMART Recovery is also a resource that teens can use to access self-empowering support, in-person meetings, and a powerful online community. These models started as face-to-face group meetings, and developed into national networks that people could use to find meetings when traveling or relocating. In response to the COVID-19 pandemic and social distancing policies, many of these organizations have rapidly developed videoconferencing models for their meetings that further increase accessibility for many people. [125] Additional initial places to search include your provider's website, as well as the website of your local or state health department. These will be reputable sources to explore for care and treatment programs or to be put in contact with other professionals who can help.

Local Resources
Local resources that offer evidence-based treatment for adolescent SUD often can be compiled from these national search engines. At a local level, there could be a multitude of resources to connect adolescents with SUD to professionals who can provide evidence-based treatment, but they may not be immediately obvious, and quality of services can be highly variable. It is important to carefully assess each local resource to determine which best meets the specific needs of the individual adolescent. Then, relevant treatment programs can be contacted to initiate assessment and treatment. Likewise, knowledge of local hospital systems, including university hospital systems and private hospital systems, can be helpful to support finding appropriate treatment.

Conclusion Summary
This research paper investigated substance use disorder in adolescents through studies conducted in the United States. By describing differences in diagnostic criteria between the DSM-IV and DSM-5, as well as the ICD-11, common indicators of SUD have been outlined. Intended primarily for medical and mental health professionals with limited knowledge of SUD, the prevalence of substance use and SUD among adolescents was presented, particularly for the commonly used substances of alcohol, nicotine, and cannabis, as well as common comorbid disorders (e.g., ODD/CD, depression, ADHD). [45] The developmental course of SUD was found to be highly dependent on many specific factors related to the individual, and thus the age of onset, temperament, and comorbidities, among other factors, affect the prognosis of SUD and influence the type of assessment and treatment offered to the individual. Numerous assessments for SUD in adolescents exist, and it is important for clinicians to consider cost, accessibility, type of substance use, and severity of use when determining which assessment is needed in the context of a specific individual at a certain point in time. Likewise, evidence-based treatments, including individual therapy, family therapy, pharmacotherapy, and Multisystemic and Multidimensional Therapy are available and may offer relief to adolescents with SUD.
A plethora of resources, both national and local, are readily available through simple internet searches that locate websites and phone lines to provide further context around preemptive risks and warning signs of SUD development, anonymous crisis support, information on how and where to receive support, and treatment clinics open to new patients. A key factor to address among adolescents who engage in substance use is enhancing and maintaining motivation to reduce substance use, since most youth are referred to substance use treatment by others (e.g., parents, school, juvenile justice system).
Having a deeper understanding of SUD and how it affects adolescents' well-being is an important first step in reducing the prevalence of SUD, negating the longterm consequences of addiction, and preparing for unexpected but relevant issues that could exacerbate mental health disorders that heighten the risk of Substance Use Disorder in adolescents.

Limitations
While this paper is a general overview of adolescent Substance Use Disorder diagnosis, assessment and treatment, this review is limited in scope to a United States context. Developmental norms for adolescents and clinical concepts of substance use and SUD vary across cultures and countries.
Similarly, context is key to determining the best treatment plans; there is no one-size-fits-all for substance use disorder. Age of onset of use, type of substance, co-occurring disorders, social determinants of health, and frequency of use, and volume of use can all drastically impact patient needs and outcomes in ways that are not fully covered in the scope of this paper.
An additional limitation to this paper is variation between states in the US on legal issues such disclosure of medical records, or the right for minors to consent to substance use treatment. Determining if, when, and how to break confidentiality to inform parents depends on the context, clinical judgements, and the minor consent laws of the specific state. [126] The variance in the legalization of recreational cannabis and medical cannabis across the US also affects the prevalence of cannabis use and variance in legal ramifications for adolescents in different states.
Finally, this paper is intended for medical and mental health professionals with limited experience with Substance Use Disorder. Therefore, this paper may be less relevant for the general public or medical and mental health professions well-versed in Substance Use Disorder.

Future Directions
Future directions for research in this field include crosscomparisons of trends in different countries as well as with research conducted in different languages. Future research may also examine the potential mechanisms driving the relationship between SUD and common comorbidities in order to better understand shared biological, psychological, social, or other factors leading to co-occurrence. Furthermore, including lifecourse trajectory perspectives is essential for understanding later-life treatment outcomes and potential interventions. This paper provided a broad overview of many substances, yet much remains unknown about what roles specific substances may play and how different substances may interact with one another. Future work should determine similarities and differences in how specific substances help maintain addiction and interact with comorbid mental health disorders.
Future reviews on adolescent Substance Use Disorder could also focus on the effect of widespread crises such as natural disasters, social unrest, and pandemics. Current research on COVID-19 has suggested increased isolation during the pandemic has heightened risks associated with SUD, such as stress, fear, and anxiety, as well as reducing the potential for intervention and treatment. [127] For example, in the cases of opioid overdose, there is a lower probability of someone being in proximity who could administer life-saving measures like naloxone. [128] Researchers have found that the usual contexts of adolescent substance use have changed in the pandemic, with increases in solitary use, which is associated with depression, and increases in using substances with parents. [129] Recent research on bipolar disorder suggests that COVID-19 presents both challenges, such as stigma, interruption of treatment, stress, and medical risks, as well as opportunities, such as increased resilience and adaptations of mental health treatment delivery, for those with bipolar disorder. [130] As the COVID-19 global pandemic continues, more research on how these impacts specifically affect adolescents with SUD can help to increase understanding of the role that external forces have on adolescents with Substance Use Disorder.
Additional Information