Residency · Residency · Medicine Pediatrics
Substance Use Disorders: From Adolescent Experimentation to Adult Addiction
Introduction
Substance use disorders (SUDs) exist on a spectrum from experimentation in adolescence to chronic, relapsing addiction in adulthood. The med-peds physician encounters this continuum regularly and must be equipped to screen, intervene, and treat across ages. Understanding the neurodevelopmental vulnerability of the adolescent brain and the chronic disease model of addiction is essential.
Epidemiology
Adolescents: 50% have tried an illicit substance by 12th grade; vaping and marijuana are the most common. Young adults (18-25): Highest rates of binge drinking, marijuana use, and opioid misuse. Adults: Alcohol use disorder affects ~15 million Americans; opioid use disorder ~2 million. Adverse childhood experiences (ACEs) strongly correlate with later substance use disorders.
Neuroscience of Addiction
The Adolescent Brain
Prefrontal cortex (decision-making, impulse control) does not fully mature until age ~25. Reward circuitry (nucleus accumbens, dopamine pathways) is highly active in adolescence. This mismatch creates a window of vulnerability for substance use initiation. Early initiation of substance use is the strongest predictor of later addiction.
Neurobiologic Model
Binge/intoxication: Dopamine surge in ventral tegmental area and nucleus accumbens. Withdrawal/negative affect: Decreased dopamine function, increased stress hormones. Preoccupation/anticipation: Prefrontal cortex dysregulation, craving.
Screening
Adolescents
CRAFFT 2.1: Validated 6-question screen for substance use in ages 12-21. Car, Relax, Alone, Forget, Friends, Trouble. Score 2+ suggests problematic use. NIAAA Youth Alcohol Screening: Age-specific questions about friends' drinking and personal drinking. Screen at every well-adolescent visit per AAP guidelines.
Adults
AUDIT-C: 3-question alcohol screen (score 4+ men, 3+ women is positive) DAST-10: Drug Abuse Screening Test. Single-question screen: "How many times in the past year have you used an illegal drug or a prescription medication for nonmedical reasons?" (any positive response warrants further assessment) SBIRT model: Screening, Brief Intervention, Referral to Treatment.
Specific Substances
Alcohol
Binge drinking: 5+ drinks (males) or 4+ drinks (females) on one occasion. Alcohol use disorder: DSM-5 criteria (2+ of 11 criteria in 12-month period) Medical complications: Liver disease, pancreatitis, cardiomyopathy, neuropathy, Wernicke-Korsakoff syndrome. Treatment: Naltrexone, acamprosate, disulfiram; CBT, motivational enhancement therapy, 12-step programs.
Opioids
Prescription opioid misuse often precedes heroin or fentanyl use. Fentanyl contamination of illicit drugs dramatically increases overdose risk. Medication-assisted treatment (MAT): Buprenorphine (X-waiver eliminated in 2023), methadone, naltrexone. Naloxone: Prescribe to all patients at risk of opioid overdose; educate families.
Cannabis
Most commonly used illicit substance in adolescents. Adolescent use associated with impaired memory, reduced IQ, increased psychosis risk. Cannabis use disorder is real and undertreated. No FDA-approved pharmacotherapy; behavioral interventions are primary treatment.
Nicotine/Vaping
E-cigarettes are the most commonly used nicotine product among youth. EVALI (E-cigarette or Vaping Product Use-Associated Lung Injury) risk. Nicotine replacement therapy, bupropion, and varenicline for cessation (limited adolescent data)
Brief Intervention and Motivational Interviewing
Express empathy; avoid judgment; Develop discrepancy between current behavior and personal goals; Roll with resistance; Support self-efficacy; Effective in both adolescent and adult populations; Even a single brief intervention can reduce risky drinking by 20-30%.
Pharmacotherapy Summary
| Substance | Medications | Notes |
|---|---|---|
| Alcohol | Naltrexone, acamprosate, disulfiram | Naltrexone also reduces craving in opioid use disorder |
| Opioids | Buprenorphine, methadone, naltrexone (IM) | MAT reduces mortality by 50%+ |
| Nicotine | NRT, bupropion, varenicline | Combination NRT most effective |
| Cannabis | None FDA-approved | CBT + motivational enhancement |
| Stimulants | None FDA-approved | CBT, contingency management |
Special Populations
Pregnant patients: Opioid use disorder treatment with buprenorphine or methadone; neonatal opioid withdrawal syndrome (NOWS) management. Adolescents: Family-based therapy is critical; confidentiality considerations. Patients with co-occurring mental health disorders: Integrated dual-diagnosis treatment.
Clinical Pearls
Screen every adolescent for substance use at every well visit using CRAFFT; normalize the conversation. The adolescent brain is uniquely vulnerable to addiction; early intervention can prevent decades of disease. Medication-assisted treatment for opioid use disorder is first-line and life-saving; all med-peds physicians should be comfortable prescribing buprenorphine. Naloxone should be co-prescribed with any opioid prescription and offered to patients with SUD and their families. Addiction is a chronic, relapsing brain disease; treat it with the same longitudinal, nonjudgmental approach used for diabetes or hypertension.
References
- Levy SJ, Williams JF, Committee on Substance Use and Prevention. Substance use screening, brief intervention, and referral to treatment. Pediatrics. 2016;138(1):e20161211.
- Volkow ND, Koob GF, McLellan AT. Neurobiologic advances from the brain disease model of addiction. N Engl J Med. 2016;374(4):363-371.
- Jonas DE, Amick HR, Feltner C, et al. Pharmacotherapy for adults with alcohol use disorders in outpatient settings: A systematic review and meta-analysis. JAMA. 2014;311(18):1889-1900.
- Hadland SE, Bagley SM, Rodean J, et al. Receipt of timely addiction treatment and association of early medication treatment with retention in care among youths with opioid use disorder. JAMA Pediatr. 2018;172(11):1029-1037.