Abnormal excretion of urinary indoles has long been implicated in mental illness. This has become well defined in two hereditary diseases with mental symptoms, namely, phenylketonuria1 and H (Hartnup) disease.2 Attempts to relate schizophrenia to indole metabolism have been inconclusive. Recent studies, however, have revealed certain Ehrlich-benzaldehyde-reacting spots, which occur more frequently, or with greater intensity, on paper chromatograms of urine from schizophrenic patients than from those of normal subjects.3-5 One such spot has been found by several investigators independently. On paper chromatograms sprayed with Ehrlich’s benzaldehyde reagent (EBR) it gives an azure-blue color and is easily located by its characteristic position in relation to urea and indoxylsulfate.4,5
The purpose of this report is twofold: (1) to describe a method for the differential extraction of indoles from urine, including the above-mentioned spot, and (2) to present results of chromatographing extracts obtained