Before World War II, a Polish chemist developing dyes stumbled across a class of chemicals that would usher in the age of psychopharmacology. Twenty years after the war, Leo Sternbach, now working in the United States, tested his discovery on himself. Two days of hallucinating later, Sternbach realized the power of his compound, diazepam, which would hit the market as Valium in 1963.

Marketed to stressed-out housewives and their executive husbands, Valium quickly became the most prescribed drug in America. At its peak in 1978, Americans consumed more than two billion tablets.

It took high-profile overdoses such as those of Elvis Presley and Liz Taylor to tarnish Valium's reputation. But Valium—made by LaRoche Pharmaceuticals where the 90—something Sternbach maintained an office in the 1990s—is still available as a prescription sedative.