Demethylation of C14 2,3,4-trimethoxyphenylethylamine in schizophrenics before and after L-methionine loading.

Demethylation was compared in acute and chronic schizophrenics and in non-schizophrenics by the administration of C14 labelled 2,3,4-trimethoxyphenylethylamine (TMPEA). The results did not show a significant difference in the urinary levels of the monodemethylated catabolites of TMPEA among any groups of patients. However, there was a significant decrease in demethylation in untreated chronic schizophrenics after ten days of L-methionine orally, whereas the non-schizophrenic group similarly given methionine did not change. This suggests the possibility of a biological weakness in schizophrenia.