Studies were made on infantile intractable epilepsy, especially on West syndrome and Lennox syndrome, from a biochemical viewpoint. As a result, some abnormalities in the serotonin metabolism were suspected; the abnormalities were considered to lead to a decrease in the secretion of ACTH. Better results in a clinical trial were obtained by the combined use of ACTH and valproic acid, which increases the amount of GABA in the brain, than by the use of ACTH alone; the combined use in an animal experiment using rats resulted in a more conspicuous increase in the amount of GABA in the brain. Moreover, the clinical effectiveness of ketogenic diet therapy was studied; in an experiment, using mice, done in order to clarify the mechanisms, a significant increase in ATP in the brain was seen, and the involvement of high-energy phosphoric acid suggested.