OUR PREVIOUS publications have been concerned with the effect of glutamic acid on mental functioning at various levels of the learning curve and over different intervals of time.1Glutamic acid was found to be beneficial not only to patients in the category of low-defective intelligence, but to persons at the high-defective and borderline intelligence levels, who were within striking distance of average intelligence.2 Once this improvement had been secured and a limit, or "ceiling," established, it was natural for us to turn our attention to the problem of the permanency, or carry-over effect, of treatment with glutamic acid following cessation of therapy. Our present paper, therefore, is a report of our findings to date after glutamic acid therapy had been discontinued from 2½ to three years. Of the 69 children and adolescents in our original study,1b38 who received glutamic acid treatment were available for psychological retesting