"Mother's Little Helper," - Valium

Valium, the drug that revolutionized the treatment of anxiety and became a cultural icon, is 40 years old this year.

The drug owes its success to the stubborn streak of chemist Leo Sternbach, who refused to quit after his boss at Hoffmann-La Roche ended a project to develop a tranquilizer to compete with a rival company's drug.

Sternbach tested one last version and in just a day, he got results: The compound made animals relaxed and limp.

Sternbach had made the discovery that led to Valium. Approved for use in 1963, it became the country's most prescribed drug from 1969 to 1982.

"It had no unpleasant side effects. It gave you a feeling of well-being," Sternbach, 95, said. "Only when the sales figures came in, then I realized how important it was."

The Roche Group, Hoffman-La Roche's parent, sold nearly 2.3-billion pills stamped with the trademark "V" at its 1978 peak.

While its name was derived from the Latin word for being strong, Valium soon picked up nicknames: "Executive Excedrin," for its use by the corporate jet set, and "Mother's Little Helper," after the title of a Rolling Stones tune about an overstressed housewife who "goes running for the shelter of a mother's little helper."