Even Occasional Cannabis Use Can Affect Teens’ Emotional Health and School Performance, Major U.S. Study Finds

A large national study from the United States is raising new concerns about teenage cannabis use, showing that even infrequent use may be linked to emotional difficulties and poorer academic outcomes. The research suggests that marijuana does not need to be used daily to have an impact—using it just once or twice a month was associated with noticeable challenges for adolescents.

The study was led by Ryan Sultán, an assistant professor of clinical psychiatry at Columbia University Vagelos College of Physicians and Surgeons, and published in the journal Pediatrics in December 2025. Unlike earlier research that mainly focused on heavy or daily cannabis use, this work looked closely at any level of use, including occasional use that many teens and adults consider harmless.

What the Study Looked At

Researchers analyzed data from a nationally representative survey of more than 160,000 U.S. students in 8th, 10th, and 12th grades. The data came from surveys conducted between 2018 and 2022, covering a wide range of regions, school types, and backgrounds.

Students were grouped based on how often they reported using cannabis:

• No use
• Monthly or less frequent use
• Weekly use
• Near-daily or daily use

Over one-quarter of respondents reported some level of cannabis use. Fewer than 20 percent said they used it monthly or less, while much smaller percentages reported weekly or near-daily use.

Academic Performance Took a Hit

One of the clearest findings involved school performance. Teens who used cannabis even once or twice a month were more likely to report problems at school compared to those who did not use it at all. These problems included lower grades, difficulty focusing, missing school, and disengagement from academic activities.

The risks increased as use became more frequent. Adolescents who used cannabis nearly every day were almost four times as likely to report poor grades. They were also far more likely to feel disconnected from school and less motivated about their future educational plans.

Importantly, these associations were stronger among younger teens, suggesting that early exposure may be especially disruptive.

Emotional Distress and Behavioral Changes

Academic issues were not the only concern. The study also found strong links between cannabis use and emotional distress. Teens who used marijuana monthly reported higher levels of:

• Depression-like symptoms
• Anxiety
• Impulsive behavior
• Difficulty regulating emotions

As with academics, the pattern followed a dose-response relationship. The more frequently cannabis was used, the more likely teens were to report emotional and behavioral challenges. Near-daily users showed the highest levels of distress.

Researchers emphasized that these effects were observed even after accounting for other factors, reinforcing the idea that cannabis use itself may play a meaningful role.

Shifting Trends in Teen Drug Use

The findings come at a time when overall substance use among U.S. adolescents is at historic lows—with one major exception. Cannabis use has remained relatively common and, in some groups, has increased.

Currently, about one in five U.S. high school students reports using cannabis. Among 12th graders, roughly 6 percent use it daily, a figure that has risen over the past decade. Changing laws, increased availability, and shifting social attitudes may all be contributing to this trend.

Another factor raising concern is the increasing potency of modern cannabis products. Today’s marijuana often contains two to three times more THC than products commonly used decades ago. THC is the primary compound responsible for the drug’s psychoactive effects, and higher concentrations may amplify its impact on the developing brain.

Why Adolescence Matters So Much

Scientists have long warned that adolescence is a critical period for brain development. During the teenage years, the brain is still building and refining neural circuits involved in learning, attention, decision-making, emotional regulation, and self-control.

Introducing cannabis during this sensitive phase may interfere with those processes. Previous research has linked adolescent cannabis use to lasting effects on memory, concentration, and executive functioning, all of which are essential for academic success.

The new study adds to this evidence by showing that these risks may begin at much lower levels of use than previously assumed.

Withdrawal and Mood Changes Can Happen Quickly

Another striking observation highlighted by researchers is how quickly some teens experience negative effects. Even after using cannabis only a few times, some adolescents show signs of withdrawal symptoms, including irritability and worsening mood.

These early changes may partly explain why occasional use is already associated with emotional distress and school problems. What starts as experimental or social use can quietly escalate into patterns that affect daily functioning.

What Parents and Caregivers Can Do

Experts involved in the study emphasize the importance of early, open, and nonjudgmental conversations about cannabis. Teens should understand that just because something is labeled “natural” does not mean it is harmless—especially for a developing brain.

Parents and caregivers are encouraged to watch for warning signs such as:

• Sudden drops in grades
• Mood swings or increased anxiety
• Loss of interest in hobbies or activities
• Changes in sleep or motivation

If these changes appear, cannabis use should be considered as a possible contributing factor, even if the teen reports only occasional use.

How This Study Fits Into the Bigger Picture

While the study is observational and cannot prove cause and effect, its large sample size and national scope make the findings difficult to ignore. The consistent pattern across academic, emotional, and behavioral measures strengthens the argument that cannabis use during adolescence carries real risks.

The research challenges a common belief that infrequent marijuana use is essentially harmless for teens. Instead, it suggests that no level of use is truly risk-free during this stage of development.

Final Thoughts

As cannabis becomes more accessible and socially accepted, understanding its impact on young people is more important than ever. This study offers a clear message: even occasional cannabis use may affect teens’ emotional well-being and school success.

For families, educators, and healthcare providers, the findings reinforce the need for awareness, honest discussions, and early intervention. For teens themselves, the research provides valuable information to make more informed decisions about their health and future.

Research paper:
https://doi.org/10.1542/peds.2024-070509