When considering their wider social effects, alcohol, heroin and crack cocaine were the deadliest. But overall, alcohol outranked all other substances, followed by heroin and crack cocaine.
Marijuana, ecstasy and LSD scored far lower.
Alcohol the most lethal drug: study
British rank substances based on how destructive they are to the individual who takes them and to society as a whole
http://www.theglobeandmail.com/life/health/alcohol-the-most-lethal-drug-study/article1780267/