Because of addiction to morphine (also used as medicine), heroin was believed to be a non-addictive drug that will reduce the addiction to morphine. It was then, later on, found that it also caused addiction and began to be controlled.
20th Century (1950-1999) Pharmaceutical
In 1952, Jonas Salk developed the polio vaccine using a dead polio virus. It reduced the polio cases in America. The last that was recorded was in 1993 when a traveler brought polio into the country.
21st Century (2000-present) Medical Practice
Tranquilizers also referred to as "happy pills" acts toward the central nervous system so they were used to decrease anxiety and insomnia. It was also used in surgeries to decrease consciousness thus less anesthetic is needed.
21st Century (2000-present) Pharmaceutical
In 1954, the first successful kidney transplant was performed by Joseph Murray
Functional magnetic resonance imaging or fMRI is used in the 21st century to measure brain activity thus diagnose mental illness by detecting changes in blood flow.
Gardasil, a vaccine to prevent cervical cancer was approved by FDA in 2006