As many as one in every 25 people worldwide uses cannabis despite the negative health effects associated with the drug, according to a new study published in the Lancettoday.
The report, which uses estimates supplied by the UN Office on Drugs and Crime, reveals that cannabis continues to be the drug most widely cultivated and used around the world.
The study indicates that 166 million adults between the ages of 16 and 64 admitted to using the drug at least once a week during 2006, equivalent to 3.9 per cent of the global population.
Cannabis use was found to be highest in the USA, Australia and New Zealand. Some African countries are also thought to have high rates of cannabis use although accurate figures were not available.
Approximately 31 per cent of all cannabis users are estimated to be from Asia, while 25 per cent and 24 per cent of users live in Africa and the Americas respectively. Eighteen per cent of cannabis users are to be found in Europe, according to the research.
Although Ireland is not covered in the study, a recent report from the National Advisory Committee on Drugs published last year revealed that about 17 per cent of adults have used cannabis in their lifetime with one in 33 of the population described as current users.
The report indicates that trends in use are highly variable within and between regions. Although Australia and New Zealand are both in the highest use category, the drug is in decline there, a trend also witnessed in other wealthy nations. In contrast, cannabis use is believed to be increasing in some low and middle income countries, particularly in Latin America and Africa.
While cannabis is widely considered to be a ‘soft drug,’ the study’s authors Prof Wayne Hall, School of Population Health, University of Queensland, Brisbane, and Prof Louisa Degenhardt, National Drug and Alcohol Research Centre, University of New South Wales, Sydney, report that the data shows that cannabis is more harmful than commonly believed.
According to the study, the average tetrahydrocannabinol (THC) content - the active component of cannabis - has almost doubled in some countries over the past decade. A high THC content has been found to lead to anxiety, depression, and psychotic symptoms in some users and also an increased dependence on the drug.
The report shows that an estimated 9 per cent of people who ever use cannabis will become dependent on the drug.
“The most probable adverse effects [of cannabis] include a dependence syndrome, increased risk of motor vehicle crashes, impaired respiratory function, cardiovascular disease, and adverse effects of regular use on adolescent psychosocial development and mental health,” said the authors.
However, they conclude that the public health burden associated with cannabis use remains modest compared with that of alcohol, tobacco and other illicit drugs.
