The most commonly prescribed psychiatric drugs are antidepressants. They treat depression and anxiety. The first ones, isoniazid and iproniazid, were discovered by accident. They were developed after the Second World War by a Swiss pharmaceutical company (from leftover German V2 rocket fuel!) as tuberculosis treatments. Some tubercular patients taking the drugs became energetic and even rowdy, and so a few curious doctors tested the drugs on psychiatric patients in 1952. Their potential as ‘psychic energisers’ received press attention. Many doctors began prescribing them to treat depressed patients in mental hospitals even though they were not officially approved for psychiatric use.
Pharmaceutical companies quickly became interested in developing drugs targeting depression. They started in the 1950s with the class of drugs called tricyclics. In the mid 1960s brain scientists hypothesised that iproniazid, the anti-tuberculosis drug, improved a patient’s mood by slowing an enzyme that breaks down the neurotransmitter serotonin. The hypothesis led to a second major class of antidepressants called monoamine oxidase inhibitors (MAOIs) which targeted the same enzyme. Despite justifiable concerns about side effects, both types of antidepressant remained drugs of choice among psychiatrists for over two decades. Their use declined after selective serotonin reuptake inhibitors (SSRIs) such as Prozac were introduced. These worked faster with fewer side effects. SSRIs also had a larger market because they treated anxiety (previously the domain of the minor tranquilisers) as well as depression.
Read Entire Article: http://www.sciencemuseum.org.uk/broughttolife/techniques/antidepressants