The Disordered Mind: What Unusual Brains Tell Us About Ourselves

by Eric R. Kandel

In 1928 Mary Bernheim, a graduate student in the Department of Biochemistry at the University of Cambridge in England, discovered monoamine oxidase (MAO), an enzyme that breaks down a class of neurotransmitters known as monoamines.6 (Neurotransmitters, as we have seen, are chemical messengers that neurons release into the synapses to communicate with other neurons.) Her discovery led to the introduction of a drug called iproniazid, which was used to treat people with tuberculosis. In 1951 doctors and nurses working on the tuberculosis ward of Sea View Hospital on Staten Island, New York, noticed that their patients taking iproniazid seemed less lethargic and much happier than those who were not taking the drug. Subsequent clinical trials revealed that iproniazid had antidepressant properties. Shortly thereafter, imipramine, a drug developed initially to treat people with schizophrenia, was also found to relieve symptoms of depression, by blocking the reuptake of monoamines into nerve terminals. Reuptake is a process that recycles the neurotransmitters and stops the signaling.