June 1992

Relationship Between Central and Peripheral Serotonin Indexes in Depressed and Suicidal Psychiatric Inpatients

Author Affiliations

From the Laboratories of Neuropharmacology, Department of Psychiatry, University of Pittsburgh (Pa) (Drs Mann and Myers and Ms Mieczkowski); Department of Psychiatry, Cornell University Medical College, New York, NY (Drs McBride, Leon, and DeMeo); Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY (Drs Brown and Stanley); and Laboratory of Clinical Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Md (Dr Linnoila).

Arch Gen Psychiatry. 1992;49(6):442-446. doi:10.1001/archpsyc.1992.01820060022003

• Serious suicidal behavior, affective disorders, and a variety of other psychopathologic behaviors and syndromes have been found to correlate with measures of the serotonin system. Clinical studies have employed a range of serotonin indexes, including the cerebrospinal fluid level of 5-hydroxyindoleacetic acid, the prolactin response to serotonin agonists, such as fenfluramine hydrochloride, and platelet serotonin-related proteins or serotonin content. Many of these indexes are correlated with suicidal behavior, but the interrelationship of these biologic measures has been uncertain. We studied the relationship of a series of serotonin indexes in patients in whom these measures were correlated with suicidal behavior. A positive correlation was found between cerebrospinal fluid 5-hydroxyindoleacetic acid and the maximal prolactin response to fenfluramine but not with platelet serotonin, receptor indexes. The fenfluramine-stimulated maximal prolactin response correlated with platelet serotonin2 receptor number, particularly in older patients. We conclude that cerebrospinal fluid 5-hydroxyindoleacetic acid measurements cannot be replaced but can be complemented by less invasive procedures, such as a fenfluramine challenge test or platelet serotonin2 measures, in the study of the relationship of the serotonin system to psychiatric disorders.