Last week, the national press reported the results of two new studies conducted into the long-term effects of cannabis use.

The first, from the Medical Research Institute of New Zealand, assessed the effects of smoking the drug on the respiratory function of users. Its authors claim to have found that the effect of a single joint on the lungs was equivalent to smoking between two-and-a-half and five cigarettes. They also noted that long-time pot smokers can develop symptoms of asthma and bronchitis, along with obstruction of the large airways and excessive lung inflation.
However, the report has been dismissed by a number of cannabis activists.
Former cannabis importer and legalisation campaigner Howard Marks told Hot Press that he was sceptical of the researchers’ claim of one joint being equal to five cigarettes. “You’d need to look at the fine details of the study,” he said. “I’d like to know the exact composition of the joint they used for comparison.”
The legendary ‘Mr. Nice’ has no objection in principle to scientific studies. He argues that it is “a good idea” to study any possible harmful effects of the drug in a thorough and scientific manner and for the results of those studies publicised. What should happen next, however, is a different matter.
Marks believes that once the research is published, “it should be up to individual users to make the decision whether they are going to smoke it or not, not some government bureaucrat”. Ultimately, Marks feels that studies such as this miss the point entirely: “The real question is whether the substance would be more harmful to society if it was regulated and controlled or if things remain as they are”.
In a separate study, the British medical journal The Lancet analysed the relationship between the cannabis use and the development of psychosis in later life.
The article was a ‘meta-analysis’ or a study of studies, that evaluated the results of numerous existing published articles and papers on the subject.
Dr. Stanley Zammit of the Department of Psychological Medicine at the University of Cardiff in Wales is one of the authors of this paper.
In an interview on the The Lancet’s official podcast, he was cautious about making any hard and fast pronouncements based on the study’s results.
“It may be that people who use cannabis are different from other people in several ways,” he said.
“For example, they may be more likely to use other drugs and it could be these, or particular personality traits, that cause the increased risk of psychosis. The studies we looked at did try to account for this and approximately half of the associations found were explained by these other factors.”
Dr. Zammit was keen to stress that uncertainty was an inevitable feature of meta-analyses such as this: “I wouldn’t go as far as to say we can be certain that cannabis use leads to increased risk of pscyhosis,” he said, “There’s always the possibility that there are other characteristics that people haven’t thought of, and haven’t adjusted for, which might explain the rest of the association.”
This is quite a different position than that which was proclaimed in newspaper headlines.
Although he admitted that the individual risk of users developing an illness such as schizophrenia is low, Dr. Zammit did warn that it could still be much higher for less severe psychotic conditions. The risk might also be particularly heavy for regular users of the drug.
“If people have any unpleasant symptoms after using cannabis, for example a lot of anxiety, or feelings of paranoia, this should be a warning signal to stop using or cut down on the frequency of their use,” he advised.
Speaking to Hot Press, Irish legalisation campaigner Luke “Ming” Flanagan (pictured) was highly critical of both the studies’ conclusions and the media’s coverage of them. “They’re saying cannabis is more harmful than tobacco, but no matter what way you ingest it, tobacco is carcinogenic, whereas cannabis is only carcinogenic when smoked,” he said.
“If cannabis was legal, the health services could advise people to eat it, drink it or inhale it through a vaporiser, which is infinitely less harmful. Let’s face it, anything you smoke is going to be bad for your lungs. You could smoke turf mold and it would be bad for you.”
Flanagan was scathing in his criticism of the media’s coverage of the studies. “They’re presenting a totally biased, one-dimensional view,” he said. “I couldn’t believe it when they used the phrase ‘in the past [hash] had been considered a less harmful drug than heroin’.”
One young cannabis user told hotpress that she had seen the reports, but that they didn’t really worry her. “To be honest, it’s nothing that I hadn’t guessed myself,” she said. “I can’t say that it will stop me smoking. I’d generally smoke less than once a month. I think that most people who smoke hash wouldn’t smoke anything like as much as a cigarette smoker would. If a cigarette smoker smoked 10 a day, then that would be the equivalent of two joints a day, going by the study results. And only the really hardcore heads would smoke that much.”
She went on to say that, while she didn’t doubt the authenticity of the studies, “it does seem like this might be just be the British government’s latest vendetta. Gordon Brown recently ordered a review of cannabis’s declassification to a Class C drug, so you could speculate that’s the reason we’re seeing this sudden surge of studies on the subject to back up that campaign.”
We haven’t heard the last of this.