Legal substances like cigarettes and alcohol tend to have more detrimental effects than cannabis and other illegal ones, according to a joint study by the Institute for Health Metrics and Evaluation, the UN Office on Drugs and Crime, and the World Health Organization. 

The study found tobacco to be the world's premiere addictive substance, with more than 15 percent of the total world population reporting regular use. Because of this high rate of consumption, cigarettes earn themselves the title of world's most detrimental substance. Alcohol landed in second place, with 20 percent of adults reporting heavy drinking in the past month.

Meanwhile, substances that are widely illegal were shown to have much lower consumption rates and statistically didn't cause as much harm. Of course, this may be related to the legal status of the substances deterring people from using them. Less than 5 percent of people reported using cannabis, with consumption rates highest in the US and Canada.

Europe, on the other hand, was shown to be the biggest consumer of both cigarettes and alcohol. Despite this trend, Europeans may experience higher life expectancy.

"Europeans proportionately suffered more but in absolute terms, the mortality rate was greatest in low and middle-income countries with large populations," the study states.

Additionally they noted that while Europe and North America reported higher substance use and addiction rates than other regions, this may be because of their more sophisticated data-collection systems. So the rates may be comparable in other regions; we just don't have a reliable way to track them yet.