Psychosomatic Medicine 14:34-40 (1952)
© 1952 American Psychosomatic Society

Correlation between Fluctuation of Free Anxiety and Quantity of Hippuric Acid Excretion

Mentally and physically healthy subjects show no significant alteration in hippuric acid excretion on repeated testing over a two-year period. Psychoanalysis of such subjects does not alter the hippuric acid excretion significantly. Patients who manifest free anxiety excrete elevated amounts of hippuric acid. Successful psychiatric treatment reduces the amount of free anxiety and hippuric acid excretion to normal levels. The variance of hippuric acid excretion in the anxiety group is significantly greater than in the control group. The coefficient of correlation of hippuric acid excretion and the clinical anxiety score is highly significant. Catatonic schizophrenic subjects, in contrast to anxiety subjects, excrete significantly less hippuric acid than the healthy controls. Successful psychiatric treatment also reduces the amount of catatonia and raises the hippuric acid excretion to normal levels. The variance of the hippuric acid excretion in the catatonic group is significantly greater than the control group. The coefficient of correlation of hippuric acid excretion and the clinical catatonic score is highly significant. Individuals exposed to mild external (real) stress, unlike anxiety or catatonic subjects, do not develop abnormal excretion patterns.