Failure to detect 3,4-Dimethoxyphenylethylamine in the Urine of Schizophrenics

Abstract

THE identification of 3,4-dimethoxyphenylethylamine in human urine1 has been confirmed by published reports from two other laboratories, each using methods different from ours2,3. We have now analysed more than 250 urine samples from acute schizophrenic patients. The findings in these studies are consistent with our original data. In addition wre have isolated sufficient quantity of 3,4-dimethoxyphenylethylamine from pooled urine obtained from schizophrenic patients to obtain a melting point (hydrochloride m.p. 152°–154° C). Therefore, the presence of this compound in urine would seem to be well established. Perry et al. imply that their failure to find 3,4-dimethoxyphenylethylamine in 10 patients on a plant-free diet demonstrates that this compound is of plant origin. However, they have not shown that they are able to detect 3,4-dimethoxyphenylethylamine in subjects eating a diet that includes plants. It is, therefore, not possible to assess their techniques in the face of the many analytical hazards involved in detecting a few micrograms of an amine in large volumes of urine. Our own in vivo and in vitro investigations using isotopes provide evidence that 3,4-dimethoxyphenylethylamine is of endogenous origin4. As we have pointed out previously, the significance of these findings in the genesis of schizophrenia cannot at present be assessed.