Abstract
The urinary excretion of 5-hydroxyindoleacetic acid (5HIAA) in terms of 5-hydroxyindoles, was studied in thirty subjects; ten normal controls, ten patients with depressive neurosis and ten patients with manic depressive psychosis, depressed type. Urinary 5HIAA, a metabolic end produce of serotonin, was determined repeatedly for all subjects, including patients before and after treatment. Results indicated significantly higher values in depressed patients and these values decreased following successful treatment. There was a significant positive correlation between the severity of depression and the patient's urinary 5HIAA values, but there was no significant difference in these values in those patients with depressive neurosis compared with depressive psychosis. Some significant positive correlations were also noted between certain symptoms rated high on the Hamilton rating scale for depression and the patient's urinary 5HIAA values.