Several recent reports (Davis and Sulzbach1; Finley and Lesko2; Polatin, Strauss and Altman3; Levy, Serota and Grinker4) have indicated permanent or semipermanent changes in the electroencephalogram following metrazol shock therapy. In the main these authors seem to agree that a large number of metrazol-induced convulsions will produce electrocortical potentials of high amplitude and very slow frequency. Until a critical number of convulsions is reached, which varies from patient to patient, there is no change in the record beyond a temporary one that is attributable to the convulsion itself (Goodwin, Kerr and Lawson5; Strauss and Rahm6). Polatin, Strauss and Altman3 reported, for instance, that in all their cases there was a return to the preconvulsion electroencephalogram within a few hours after the administration of metrazol, until some number of convulsions, up to 12, was reached, after which severe and more than transient mental changes