Definitively ranking how addictive various substances are is tough work, even for scientists.
Each of us reacts differently to distinct drugs, from the pleasurable reaction we experience when we use the substance to the cravings or even physical discomfort we feel when we're suddenly deprived of it. Nevertheless, a group of addiction experts, including specialists from the Royal College of Psychiatrists as well as chemists, forensic scientists, and pharmacologists, took a stab at listing them by averaging numerous aspects of addiction.
Their work was published in the journal The Lancet in 2007. Here's what they came up with:
