Prof Terrie Moffitt
Media playback is unsupported on your device

Young cannabis smokers run risk of lower IQ, report claims

Young people who smoke cannabis run the risk of a significant and irreversible reduction in their IQ, research suggests.

The findings come from a study of around 1,000 people in New Zealand.

An international team found those who started using cannabis below the age of 18 - while their brains were still developing - suffered a drop in IQ.

Prof Terrie Moffitt of King's College London's Institute of Psychiatry is one of the team who worked on the research.

  • 28 Aug 2012
Go to next video: Could legalising marijuana save the economy?