Experts Ranked the Top 5 Most Addictive Substances December 22, 2016 Chris Aguirre via The Science Explorer David Nutt, a psychiatrist and neuropsychopharmacologist who specializes in drugs research, and his co-researchers put together a ranking system for addictive substances, comprising a list of the five most addictive substances on Earth. Source: http://thescienceexplorer.com/brain-and-bo...