Test for decreased serotonin/tryptophan metabolite ratios in abstinent alcoholics.

A segment of the population has a defect in the metabolism of tryptophan that causes a lowered concentration of serotonin in the central nervous system and indicates a predisposition towards chronic alcoholism. The metabolic defect in tryptophan metabolism is in the pathway between tryptophan and 5-hydroxyindoleacetic acid (5-HIAA) but not in the other pathways of tryptophan metabolism. A test using HPLC with amperometric detection was developed to detect the presence of an impaired serotonin metabolic pathway and therefore indicate a predisposition towards chronic alcoholism. The test used a ratio between 5-HIAA and two metabolites (indoleacetic acid and anthranilic acid) from the other pathways of tryptophan metabolism to indicate the presence or absence of an impaired serotonin metabolic pathway while correcting for variations in the concentration of urine.