Tridione (Abbott) is 3.5.5-Trimethyloxazolidine-2, 4-dione, and has been demonstrated clinically to have an inhibitory effect on petit mal, myoclonic and psychomotor seizures in epilepsy. Gibbs, Gibbs and Lennox first demonstrated a similarity between the cortical dysrhythmias in certain cases of schizophrenia and those of psychomotor epilepsy, whilst Kalinowsky and Putnam, as a result of these findings, gave the anti-convulsant dilantin as a successful sedative to 60 cases showing mental symptoms. Since tridione has a specific action against psychic equivalents in epilepsy, it was thought that its administration to patients showing chronic mental disturbances might result in at least a similar improvement.