This was a form of treatment for schizophrenia and other forms of psychosis which was developed in the 1930's and was widely used during the 1940's and 1950's, prior to the development of anti-psychotic medication.
The full-blown version of the treatment involved the administration by injection of large doses of insulin which would induce a coma, although a 'modified' version, using sub-coma dosages was also used.
In America, the use of Insulin shock therapy had virtually died out by the 1970's, although it continued to be used in some parts of the world.
Nowadays it is generally considered to have been an ineffective, dangerous and inhumane form of treatment.
Sylvia Plath received Insulin shock therapy during her stay at McLean Hospital.
Click here to see a video about Insulin Shock Therapy.