Cannabis and IQ debate in the media

A Norwegian economist has questioned the findings of a highly publicised New Zealand study which found a causal link between heavy adolescent cannabis use and a decrease in IQ. However, the authors of the original research have backed their conclusions in the ensuing media coverage.

Research published last year, based on data from the Dunedin cohort study, found that the heavy teen cannabis use led to a decrease in IQ. But now economist Ole Rogeberg from the Ragnar Frisch Centre for Economic Research has published an analysis of the study claiming that the the association between teen cannabis use and IQ could be due socio-economic factors the original authors did not account for.

The authors of the Dunedin research have refuted these claims, saying their research does show a causal effect.

You can read more about the challenging of the NZ research and the authors’ response here.

The disagreement, based around the controversial issue of teen drug use, has unsurprisingly generated a great deal of media coverage.

Local NZ coverage includes:

3 News: NZ-based research into cannabis-IQ link criticised
TVNZ News: Smoking dope may not harm IQ – study Teen cannabis smokers not harming IQ – study
NZ Herald: Cannabis effects not to blame for IQ loss – study

Examples of international reporting include:

Nature News: Pot smokers might not turn into dopes after all
US News and World Report: Pot Use-Low IQ Link Challenged in Study
ABC News: Link Between Pot Smoking and IQ Drop Challenged
Smithsonian Blog: Long-Term Marijuana Use Could Have Zero Effect on IQ
NBC News: Does pot really lower IQ? It’s not so simple
The Australian: Dope may not produce dopes
Huffington Post: Marijuana Study Tying Teens’ Pot Use To I.Q. Drop Is Flawed, New Paper Suggests
Yahoo! News: Link between pot smoking and IQ drop challenged
Business Insider: Cannabis Use Teens Lower IQ