In the 1990s, Dr. Jack E. Henningfield of the National Institute on Drug Abuse as well as Dr. Neal L. Benowitz of the College of The Golden State at San Francisco each placed the 6 most addicting medications. Mistreating this class of medications can lead to extreme health issue, including dependency and overdose. Indicators of barbiturate overdose include clammy skin, dilated pupils, superficial breathing and coma.