A Washington Post article today reveals a new cannabis prevention campaign targeting teenagers in Colorado. Unfortunately, the state which has shown the freethinking boldness to legalize marijuana for adults is implementing some of the same, long-debunked nonsense typical of drug prevention efforts. The campaign uses human-sized rat cages, adopting the mantra that teenagers using marijuana are lab rats for the study of how weed corrupts the vulnerable teenage brain. The campaign will rear its ugly head basically everywhere a teen might go: school, malls, movie theaters, concert venues, skate parks, and Rockies games.
Unfortunately, the campaigners haven’t been keeping up with the research documenting that such media campaigns not only fail to curb teenage drug use; they actually come with a variety of negative side effects.
1. Drug prevention campaigns normalize drug use
As an article in the Journal of Epidemiological Health explains:
Since 1998, the National Youth Anti‐Drug Media Campaign in the USA has received more than US$1.2 billion of government funds to develop and deliver interventions designed to prevent primarily cannabis use in young people. Through a variety of media resources, it has tried to foster antidrugs attitudes by portraying the negative consequences (eg poor academic achievement) and by using positive peer support, role models and developing drug‐refusal skills. However, comprehensive evaluation of the campaign (validated by the US government2) found no evidence that exposure to it affected initiation or cessation of cannabis use or antidrugs attitudes. Given previous research on such didactic techniques, it is perhaps not surprising that the campaign failed to achieve positive health changes.3,4 However, this does not mean that such well‐targeted and easily recalled social marketing campaigns achieved no change at all. Importantly, greater exposure to the US anti‐drug advertisements was associated with an increase in the belief among young people that their peers used cannabis regularly (ie descriptive normalisation); individual misperceptions of higher drug use prevalence in general and peer populations are strong predictors of intention to use.5,6
In other words, teenagers will interpret the signs and messages about cannabis use – at schools, malls, skate parks, movies, public libraries, baseball games, concert theaters, and elsewhere – as indicating that many of their peers smoke weed. Basically, whenever they go out in public, they will be reminded (by the drug prevention efforts) that teenagers smoke marijuana. And, as the article says, it is well known that thinking your peers use drugs predicts an intention to start using drugs.
2. Iatrogenic Effects of drug prevention campaigns
Basically, media campaigns to reduce cannabis use among teenagers purports uncertain medical claims (e.g., cannabis causes schizophrenia; cannabis reduces motivation) as fact. This could have self-fulfilling effects through the psychological mechanisms of stereotype-threat, a kind of negative twist to the placebo effect. The Journal of Epidemiological Health article continues:
By routinely purporting mental dysfunction as a consequence of cannabis (in itself controversial), users (and even ex‐users) may begin to believe they are experiencing such effects.7 Consequently, cannabis users in the UK may suffer amotivation, memory loss or even paranoia, not as a direct result of the drug, but through psychological mechanisms induced through high‐profile social‐marketing campaigns that effectively “sell” such negative effects. Through causal attribution, primary healthcare professionals may also be less likely to explore alternative aetiologies in known substance users. Of course, real adverse phenomena associated with substance use is well documented, but research has shown that exposure of ecstasy users to suggestions of drug‐induced brain damage and memory loss is related to their performing worse in psychological tests.8 Thus, belief can be a significant component in developing ill health (akin to “worried well” effects) much as it can be in generating feelings of health through placebo effects.9 Given that over eight million people in the UK alone have used cannabis, any iatrogenic effects of campaigns in this area alone could have major repercussions for public health.
The article concludes by pointing out that governments would never consider approving a pharmaceutical without rigorous evidence of its efficacy and safety. Meanwhile, we have ample evidence that these kinds of campaigns not only fail to decrease drug use – they often increase it – but also that there are multiple reasons to worry about iatrogenic side-effects. Yet we continue to spend money on cannabis campaigns that could be spent on, say, testing rape kits.
[image source: http://img.washingtonpost.com/blogs/govbeat/files/2014/08/CGO-CageSignLarge-B.jpg%5D
Michael Zoorob 
