Introduction
At the time of our last publication on glutamic acid treatment, in 1951, accurate appraisal of its effectiveness was difficult because of controversial findings as to degree and nature of changes following therapy. Since we had stressed intellectual aspects of improvement, it was natural for early investigators to follow that trend and to try to duplicate our results. Success or failure of therapy was usually judged in terms of point gains or losses on psychological retest, with emphasis upon group statistics rather than upon individual clinical change.Several studies appeared, nevertheless, showing the value of glutamic acid in cerebral functioning (regardless of alteration or lack of change in intelligence following therapy), results of which suggested that further investigation of the drug was warranted. As early as 1948, for example, Waelsch1 reported on the global effect of glutamic acid in a biochemical consideration of mental deficiency. "It seemed that