An estimated 200 million people worldwide use illegal drugs every year, according to a new study in Australia’s medical journal, The Lancet. The health consequences of this use include overdose, dependence, violence or injury due to intoxication, as well as heart disease, mental disorders and cirrhosis. The report found that marijuana is the most used drug, followed by amphetamines, cocaine, and opioids. It also found that illegal drug use is highest in developed countries and those who use illegal drugs usually use more than just one type. According to the World Health Organization, drugs caused 2.1 million years of life lost in 2004, followed by alcohol, which caused a loss of 1.5 million years. Drug-related deaths tend to strike younger people, accounting for the higher number of years of life lost compared with other causes of death.