Do the media talk down to teenagers over drugs?

According to the report, people who use the drug regularly by the age of 15 in particular are putting themselves at risk. But the same study also suggests no link between occasional use and academic achievement.

The study, published by the Avon Longitudinal Study of Parents and Children, also warns that it is difficult to distinguish between the impact of cannabis and that of other factors, such as alcohol.

And, according to one of its authors, the reporting of studies around drugs such as this can leave young people more confused because the issues are often oversimplified and subject to spin.

University College London professor Val Curran said that newspaper reports on the issue were often “as clear as mud”.

[Young people] are not stupid and they want to be informed about drugs. Val Curran, University College London

And the lead researcher on the study, which surveyed more than 2,200 people, Claire Mokrysz from University College London, told BBC News: “It’s hard to know what causes what. Do kids do badly at school because they are smoking weed, or do they smoke weed because they’re doing badly?

“This study suggests it is not as simple as saying cannabis is the problem.”

In recent years, the Daily Mail has reported that cannabis use doubles the risk of developing psychotic disorders, that it may trigger heart attacks and that it causes mental illness.

The Independent newspaper has reported that the drug is widespread and “less addictive than nicotine and alcohol”, that it is linked to the prevention of diabetes and that the chief minister of the Isle of Man has spoken in favour of its decriminalisation.

The Daily Telegraph has reported that the number of cannabis users suffering from mental health issues doubled in a four-year period, that the drug is as addictive as heroin and that the health dangers have been “underestimated”.

The Guardian, for its part, has reported research that suggests that – while dangerous to teenagers – cannabis is less harmful to adults. Its commentators have also written in favour of giving it to the terminally ill, and its Sunday sister paper has reported that legalisation would be worth £1.25bn to the exchequer.

“When we do our research, we want it to have an impact in the real world, we want to give the best advice. But we find it frustrating that, so often, the media give exaggerated headlines. Sometimes, it is even untrue and you wonder if the journalist has read the piece,” said Professor Curran.

She cited, in particular, the front-page piece in the Daily Mail from earlier this month on research by Professor Wayne Hall, a drugs adviser to the World Health Organisation.

The “devastating 20-year study”, the Mail’s online headline read, “finally demolishes claims that smoking pot is harmless”.

“That was not what the article was saying at all,” said Professor Curran. “It depends on the spin you put on it, which is a shame. It does an injustice to young people. They are not stupid and they want to be informed about drugs. But, because of those headlines, they think they are just being spun a line. It is not fair.”

‘Risky behaviours’

She said the BBC’s report was balanced but that it suffered from the same problem as many others – an oversimplified headline, which she said “should perhaps have had a question mark because the whole point was that there has been a series of studies reporting various different things”.

She continued: “Kids who use cannabis often also drink or take more risks playing sport – they could be in a gang. If you engage in one risky behaviour, you are more likely to also engage in more.

“What this report has shown is that, if you take into account other risky behaviours, then there is that little add-on effect that is due to cannabis. It is more to do with your lifestyle.

“One other classic example is that the Daily Mail said, if you drive when you have been smoking cannabis, you are more likely to have a road traffic accident. But they did not mention that you are eight times more likely to do so if you drive when you have been drinking. They treat illicit drugs one way but alcohol the other.”