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Study breakdown

Middle schoolers exposed to more medical marijuana ads were more likely to use marijuana a year later

Longitudinal CohortModerate evidence
The takeaway

Among 8,214 middle school students, greater exposure to medical marijuana advertising predicted higher marijuana use and stronger intentions to use one year later, in a reciprocal relationship.

Read this if you're a parent concerned about how cannabis marketing might affect your child.

8,214 middle schoolers: ad exposure predicted use 1 year later

What the researchers found

Researchers surveyed 8,214 sixth-to-eighth graders in 16 Southern California middle schools in 2010 and 2011, assessing their exposure to medical marijuana advertising and their marijuana use and intentions. Cross-lagged regression analysis revealed a reciprocal relationship.

Greater initial exposure to medical marijuana ads was significantly associated with higher probability of marijuana use and stronger intentions to use one year later. In the reverse direction, students who already used marijuana or had stronger intentions to use reported greater advertising exposure a year later, suggesting they were more attuned to noticing these ads.

The findings parallel what has been documented with alcohol and tobacco advertising: exposure to product marketing increases youth interest and use, creating a reinforcing cycle.

Why it matters

As more states legalize cannabis, advertising becomes more prevalent. This study provides early evidence that medical marijuana ads influence adolescent attitudes and behavior, similar to findings for alcohol and tobacco, supporting the case for advertising regulations.

The numbers in context

8,214 students surveyed across 16 middle schools. 50% male, 52% Hispanic, mean age 13. Greater ad exposure predicted higher use and stronger intentions 1 year later. The relationship was bidirectional.

How the study worked

Longitudinal survey of 8,214 students (50% male, 52% Hispanic, mean age 13) across 16 middle schools in Southern California. Assessed in 2010 and 2011. Cross-lagged regressions examined bidirectional relationships between advertising exposure, marijuana intentions, and marijuana use.

What this study cannot tell us

Southern California sample during an early period of medical marijuana may not generalize to other regions or current recreational markets. Self-reported advertising exposure and marijuana use. Other factors could explain both increased ad exposure and increased use.

How to read the evidence

Large longitudinal survey with cross-lagged analysis allowing bidirectional testing, but observational design limits causal claims.

When this study was published

Published in 2015 using 2010-2011 data, before recreational legalization expanded.

The bigger picture

Advertising influences behavior, particularly in young people. The parallels between cannabis advertising effects and those documented for alcohol and tobacco suggest that as cannabis markets mature, similar advertising restrictions may be needed to protect youth.

Questions still open

  • Do current recreational cannabis ads have stronger effects than the medical ads studied here? Are there advertising formats that are particularly influential on adolescents? Would regulations similar to tobacco advertising restrictions reduce youth exposure?

Common questions

Do cannabis ads affect teenagers?
In this study of over 8,000 middle schoolers, greater exposure to medical marijuana ads predicted higher marijuana use and stronger intentions to use one year later. The relationship was similar to what has been found for alcohol and tobacco advertising.
Should cannabis advertising be regulated?
The authors argued that cannabis advertising should be considered for regulation similar to alcohol and tobacco, based on their findings that medical marijuana ads influenced middle school students' attitudes and behavior.

Read the original research

Gateway to curiosity: Medical marijuana ads and intention and use during middle school.

Psychology of addictive behaviors : journal of the Society of Psychologists in Addictive Behaviors, 29(3), 613-9

Citation

D'Amico, Elizabeth J; Miles, Jeremy N V; Tucker, Joan S. (2015). Gateway to curiosity: Medical marijuana ads and intention and use during middle school.. Psychology of addictive behaviors : journal of the Society of Psychologists in Addictive Behaviors, 29(3), 613-9. https://doi.org/10.1037/adb0000094

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