RT Journal
A1 Marks M
T1 GLutamic acid and intelligence
JF Journal of the American Medical Association
JO Journal of the American Medical Association
YR 1949
FD March 5
VO 139
IS 10
SP 663
OP 663
DO 10.1001/jama.1949.02900270047019
UL http://dx.doi.org/10.1001/jama.1949.02900270047019
AB To the Editor:— 
    I read with a great deal of interest the editorial in The Journal, Dec. 25, 1948, page 1231, on the subject "Glutamic Acid and Intelligence." Any therapeutic measure which would offer even a glimmer of promise in helping the mentally retarded would indeed be a blessing. But, unfortunately, in some of the studies which were done, even though they were preliminary studies and the conclusions were not final, the subjects and the experimental conditions were not carefully controlled.An example of this type of study may be seen in "A Group Study of the Effect of Glutamic Acid Upon Mental Functioning in Children and Adults" by Zimmerman, Burgemeister and Putnam in Psychosomatic Medicine (9: 175-183 [May-June] 1947). Only a few points will be mentioned, but, in my opinion, these are significant enough to invalidate any conclusions drawn.They are:The definition of subjects is poor. The