A man smokes marijuana during an annual 4/20 rally on Parliament Hill in Ottawa, Canada, April 20, 2016.
A man smokes marijuana during an annual 4/20 rally on Parliament Hill in Ottawa, Canada, April 20, 2016. Reuters/Chris Wattie

UK researchers have found that cannabis smokers who put tobacco in their joints are more likely to get addicted. Likewise, those who do not mix tobacco are far more likely to quit, if they want. Thus, it is way better to smoke marijuana on its own to reduce harm.

University College London doctoral student at the clinical psychopharmacology unit, Chandni Hindocha, led the research on the popularity of various modes of cannabis consumption across the world. Hindocha found a link between using marijuana with tobacco and users showing symptoms of dependence and addictive behaviour.

“Cannabis dependence and tobacco dependence manifest in similar ways, so it is often difficult to separate these out in people who use both drugs. Cannabis is less addictive than tobacco, but we show here that mixing tobacco with cannabis lowers the motivation to quit using these drugs,” Hindocha said in a statement.

According to the new study published in the journal Frontiers in Psychiatry, users mix tobacco with cannabis not only to save money but also increase the efficiency of cannabis inhalation. Such mixing may increase the dependence.

Hindocha analysed responses from 33,687 cannabis users who participated in the 2014 Global Drug Survey along with collaborators from the University of Queensland, University College London and South London and the Maudsley NHS Trust. The survey is anonymous an online survey of drug use, conducted each year in partnership with international media, such as the Huffington Post, Libération, The Guardian and Die Zeit.

“Our results highlight the importance of routes of administration when considering the health effects of cannabis and show that the co-administration of tobacco and cannabis is associated with decreased motivation to cease tobacco use, and to seek help for ceasing the use of tobacco and cannabis,” said Michael T. Lynskey, Professor of Addictions in the National Addictions Centre of the Institute of Psychiatry, Psychology & Neuroscience at King's College London.

Lynskey added that research focus should be on reducing use of routes of administration that involve the co-administration of tobacco. Results suggested only 51.6 percent of Australian and 20.7 percent of New Zealand cannabis users use tobacco routes while 77.2 percent and 90.9 percent of European cannabis users use the routes.

While tobacco routes were found to be least popular in the Americas (used by only 16 percent of Canadian, 4.4 percent of US, 6.9 percent of Mexican and 7.4 percent of Brazilian cannabis users), a non-tobacco route, cannabis vaporisers, were pretty common in Canada and the US but rare everywhere else.

The study also found cannabis users who used non-tobacco routes had 61.5 percent higher odds of wanting professional help to use less cannabis and 80.6 percent higher odds of wanting help to use less tobacco. This was in comparison to those who preferred tobacco routes. Moreover, the non-tobacco route users had 10.7 percent higher odds of wanting to use less tobacco and 103.9 percent higher odds of actively planning to seek help to use less tobacco.