[Recreational use of cannabis: From effects to harm. Epidemiological data]

As the medical use of so-called "therapeutic cannabis" is in the process of being approved in France, the opening to its recreational use is the next logical step, as it has been always the chronology followed in all countries. Indeed, those who have legalized the drug have previously approved its therapeutic use. This "justifying a project phase" stage seems unavoidable. Therefore, it is appropriate to recall the effects and misdeeds of the drug during its recreational use. The general population surveys carried out in France for 25 years by public health France and the French Observatory of Drugs and Drug Addiction, have followed the evolution of psychoactive substances consumption. Particular attention was focused on cannabis use, which, in a context of wide dissemination for a quarter of a century, rose steadily higher among younger generations, but also among older adults. France is the European country with the highest prevalence of cannabis use among young people and adults. Last 25 years, its diffusion has continued to expand, and the experimentation rate multiplied by near 4. Estimated at 12.7% in 1992, it reached 44.8% in 2017. Moreover, 25% of users in the year aged from 18 to 64 years old were at high risk of problematic use or dependence in 2017. This figure is worrying because it is constantly increasing; it affects 3% of 18-64-year-old, just over a million people.