A huge amount of various therapies has been introduced during the last decennia for treatment of schizophrenia. However, the number of patients that suffers from increasing disabilities remains impressive. This justifies the search for new strategies. In this search, knowledge of previous strategies is necessary. In this article an overview is given of the literature of the method and the effects of Insulin Coma Therapy (ICT), a therapy which was used on a large scale for over twenty-five years. In conclusion it is stated that rejecting the ICT completely in the treatment of patients with schizophrenia might be too premature. Also recent results with the so-called `small ICT', new findings in animal research, and results from PET-studies of cerebral glucose metabolism invite for further study.