A team of researchers all across Canada set out recently with a simple purpose: “to evaluate the efficacy of school-based approaches to preventing and reducing substance use for children and adolescents.” The study was just published in the International Journal of Mental Health and Addiction. The results are anything but encouraging.

The researchers systematically reviewed 43 previous systematic reviews and meta-analyses. They combined that with 11 years of data, including 60 randomized controlled trials (RCTs). Focusing on students aged five to 18, the researchers asked how “school-based programs targeting the prevention or reduction of substance use compared to education as usual or no intervention.”

What they found, first and foremost, is a mess. Dozens of different programs, each with unique design elements, make the data almost impossible to compare. According to researchers, the majority of reviews were of “critically low quality” as measured by AMSTAR-2 rating criteria.  They sadly summarize:

Low-quality evidence and heterogeneous outcome measures necessitate cautious interpretation.

Now let’s have a look at the effectiveness of school-based substance use interventions on a substance-by-substance basis, and see how they fared:

Tobacco: “Moderate-quality evidence showed reduced short-term prevalence with teaching and learning interventions.”

What does that mean? The devil is in the details. It means that with tobacco abuse prevention programs, students showed a slight decrease in substance abuse after 12 months. However, students who received the training showed a slight increase in nicotine abuse after two years.

Alcohol: “Low-quality evidence indicated minimal effect of teaching and learning interventions.”

What does that mean? It means the alcohol abuse prevention trials they examined (nine RCTs) were of “low quality” and overall there was “little to no effect on alcohol use up to 12 months [after the intervention].” Further, researchers found that interventions to reduce binge drinking resulted in “little to no effect up to 12 months follow-up.”

Cannabis: “No significant effects.”

What does that mean? After reviewing 11 RCTs, the researchers concluded that school programs to reduce cannabis abuse had zero measurable impact on the rate of student cannabis use in the following 12 months. They also had zero impact “beyond 12 months.”

Illicit Drugs: “Ineffective.”

What does that mean? It means that after reviewing eight RCTs, researchers concluded that the use of illicit drugs increased for students who had received classroom substance abuse avoidance training.

Wow, that was rough! Possibly one of the largest reviews of school-based substance use interventions ever conducted, using nationwide records from a country with nationalized healthcare and comprehensive medical records, finds that school-based substance use prevention programs suck, yielding no measurable improvement and, in fact, leading to higher rates of student substance abuse.

One of the systematic reviews studied by researchers found a “small effect” in early adolescence, a “limited effect” in middle adolescence, and “no effect” in late adolescence.

Oh Canada! What are you teaching your children? In the U.S., we have also found our school-based substance abuse interventions to be largely ineffective. Programs such as D.A.R.E. that try to scare children are counterproductive. But we have also found a few things that really do work.

Try music therapy. Try art therapy. Students who receive these interventions show decreases in later substance use. Their dates of first substance use are delayed, and their percentage of adolescent substance use problems decreases. Even recess has a greater impact on substance use than “teaching and learning” anti-drug interventions.

One of the only school-based substance use interventions we can recommend is LifeSkills Training (LST). The multi-year program succeeds by limiting drug resistance skills to one module and focusing on self-management skills and social skills.

They teach important life skills such as goal setting, performance measurement, decision-making, and problem-solving. These skills boost confidence and increase resilience in the face of peer pressure. They also teach students how to be effective communicators and how to de-escalate tense situations.

LST was the subject of a 2022 study in Frontiers in Digital Health that found the digital version of LST “produced significant effects on smoking, e-cigarette use, alcohol use, drunkenness, marijuana use, and the misuse (sharing) of prescription drugs.” The U.S. Department of Justice’s National Gang Center credits LST for cutting alcohol, tobacco, and marijuana use by over 50% and polydrug use by 66% six years out.

It’s very difficult to determine from the large Canadian study exactly what was being taught to the students, but very easy to determine its effectiveness: next to none. Those parents, educators, and caregivers looking to stem the tide of teenage substance use disorders should focus on building children’s self-esteem and equipping them with a toolkit for coping with stressful situations.

Written by Steve O’Keefe. First published February 9, 2026.

Sources:

“School-Based Substance Use Interventions: An Overview of Systematic Reviews and Meta-analysis,” International Journal of Mental Health and Addiction, January 23, 2026.

“Effectiveness of a hybrid digital substance abuse prevention approach combining e-Learning and in-person class sessions,” Frontiers in Digital Health, August 2022.

“LifeSkills Training,” National Gang Center, U.S. Department of Justice, April 7, 2021.

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