Opioids and cannabis account for the greatest overall harm globally, though the severity of impacts differs.

• Combined evidence from country rankings of most harmful drugs and global indicators on deaths, drug use disorders and people in drug-related treatment point to opioids and cannabis resulting in most harm overall, across drug types.
• Opioids lead to the most severe harm as they cause the majority of drug-related deaths. Cannabis accounts for the largest share of people with drug use disorders – also reflecting the much higher number of people using cannabis compared with other drugs.
• There are some differences by gender. For example, sedatives and tranquilizers play a greater role among women, being ranked as the leading cause for drug-related deaths in 13 per cent of countries (compared with 3 per cent for men). Similarly, in drug-related treatment, sedatives and tranquilizers used non-medically play a more important role among women than among men.