Child mental health

Warning Signs of Drug Use in Teens

Save

No single behavior confirms teen drug use. Watch for clusters of change — slipping grades, new friends, mood swings, sleep or appetite shifts, and secrecy — that persist over weeks. Many overlap with depression or anxiety, so pair your observations with a calm, non-accusatory talk and, if needed, a pediatric screen.

Last updated: July 2026History

Talk to a clinician

A pediatric clinician

Gale can help you find one in your state and request a visit.

Find care →

Why one sign is rarely enough

Adolescence is a time of rapid change, so moodiness, new interests, and a desire for privacy are normal. What raises concern is a cluster of changes that appear together and persist over weeks. Substance use disorders most often begin during adolescence, which is why this developmental window gets so much attention 1. At the same time, national survey data show that adolescent use of most substances has held at historically low levels in recent years, so a worrying sign is not a foregone conclusion 2. The goal is to notice patterns without jumping to conclusions.

Behavioral and emotional signs

Behavioral shifts are often the first thing parents notice. These can include a noticeable drop in school performance, loss of interest in sports or hobbies, increased secrecy about whereabouts and online activity, new friend groups paired with dropping old friends, irritability or hostility, and sudden changes in mood or energy. Because these same changes can signal depression, anxiety, or a stressful event, they point to something worth understanding rather than to a specific cause.

Physical and practical signs

Physical clues may include changes in sleep (sleeping much more or much less), shifts in appetite or weight, red or glassy eyes, frequent nosebleeds, unusual smells on clothing or breath, or poor coordination. Practical signs include unexplained need for money, missing money or valuables, or finding unfamiliar containers, paraphernalia, or vape devices. Any one of these has innocent explanations, but several together over time deserve a closer, caring look.

How to respond at home

Lead with curiosity, not confrontation. Pick a calm, private moment, name what you have noticed without accusation ("I've noticed you seem more tired and your grades slipped — how are you doing?"), and listen more than you talk. Keep the door open for future conversations. Avoid threats and ultimatums, which usually shut down honesty. If your teen discloses use, stay calm; your steady response makes it more likely they will keep talking to you.

When to involve your teen's pediatrician

If the changes persist, escalate, or come with falling grades and withdrawal, your teen's pediatrician is a good next step. Pediatricians are encouraged to routinely screen adolescents for substance use and to deliver SBIRT — screening, brief intervention, and referral to treatment — as part of preventive care 3. A clinician can use a validated, developmentally appropriate screen such as the CRAFFT, which was built specifically to detect adolescent alcohol and drug problems 4, and brief frequency-based screeners like S2BI or BSTAD that sort risk into clear levels 56. A clinician also helps by ruling out medical or mental-health causes for the same symptoms, and by coordinating with school when grades and attendance are affected. If a concern is confirmed, they can connect your family with treatment tailored to a teen's developmental needs rather than adult programs 1.

Common questions

Yes. Many warning signs — mood changes, withdrawal, sleep and appetite shifts, falling grades — overlap heavily with depression and anxiety. That is exactly why a clinician's evaluation is useful: a pediatrician can screen for both substance use and mental-health concerns rather than guessing.

Searching can damage trust and rarely settles the question on its own. Many families start instead with a calm, direct conversation and a check-in with the pediatrician. If you do search out of genuine safety concern, be honest with your teen about why.

There is no exact number. A single change usually reflects normal adolescence. A pattern of several changes that persist over weeks, especially with a clear drop in functioning at school or home, is the signal to seek a professional opinion.

Related

Say it back

How would you explain this to someone you love?

Two or three sentences, just as you’d say it. Gale reflects back what you focused on — a mirror, not a quiz.

If things feel heavy, a person is available anytime — call or text 988.

Talk to a clinician

A pediatric clinician

Gale can help you find one in your state and request a visit.

Find care →

When to seek care sooner

  • —Signs of being acutely intoxicated, very drowsy, or unable to be fully woken
  • —Talk of wanting to die, hopelessness, or self-harm
  • —Sudden severe confusion, agitation, or paranoia
  • —Use of opioids, pills not prescribed to them, or unknown substances
  • —A rapid, escalating decline in mood, grades, or daily functioning

If your teen is unresponsive, struggling to breathe, or in immediate danger, call 911. If there are thoughts of suicide or self-harm, call or text 988 (Suicide & Crisis Lifeline), or text HOME to the Crisis Text Line at 741741.

This article is general health education and is not a diagnosis or a substitute for care from your child's clinician.

Did this answer your question?

References

  1. 1.National Institute on Drug Abuse (NIDA) (2014). Principles of Adolescent Substance Use Disorder Treatment: A Research-Based Guide. National Institute on Drug Abuse (NIH). link ✓Adolescence is a key developmental window for the onset of substance use disorders, and effective adolescent treatment differs from adult treatment and should be tailored to developmental needs.
  2. 2.National Institute on Drug Abuse (NIDA), NIH; conducted by University of Michigan (Monitoring the Future) (2024). Reported use of most drugs among adolescents remained low in 2024 (Monitoring the Future survey). National Institute on Drug Abuse (NIH). link ✓National Monitoring the Future data show adolescent use of most substances has held at historically low levels.
  3. 3.Levy SJL, Williams JF, AAP Committee on Substance Use and Prevention (2016). Substance Use Screening, Brief Intervention, and Referral to Treatment. Pediatrics. doi:10.1542/peds.2016-1211 ✓The AAP recommends that pediatricians routinely screen adolescents for substance use and deliver SBIRT as part of preventive care.
  4. 4.Knight JR, Shrier LA, Bravender TD, Farrell M, Vander Bilt J, Shaffer HJ (1999). A new brief screen for adolescent substance abuse. Archives of Pediatrics & Adolescent Medicine. doi:10.1001/archpedi.153.6.591 ✓The CRAFFT was originally developed and first validated as a brief, developmentally appropriate screen for adolescent alcohol and other drug problems.
  5. 5.Levy S, Weiss R, Sherritt L, Ziemnik R, Spalding A, Van Hook S, Shrier LA (2014). An electronic screen for triaging adolescent substance use by risk levels. JAMA Pediatrics. doi:10.1001/jamapediatrics.2014.774 ✓The S2BI single past-year frequency question discriminates among no use, use without disorder, and mild/moderate vs severe substance use disorder.
  6. 6.Kelly SM, Gryczynski J, Mitchell SG, Kirk A, O'Grady KE, Schwartz RP (2014). Validity of brief screening instrument for adolescent tobacco, alcohol, and drug use. Pediatrics. doi:10.1542/peds.2013-2346 ✓The BSTAD identifies problematic adolescent tobacco, alcohol, and marijuana use using past-year frequency cut points.

6 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — every citation independently verified. Editorial policy

← Back to the health library