Platelet Serotonin, Monoamine Oxidase Activity, and [3H]Paroxetine Binding Related to Impulsive Suicide Attempts and Borderline Personality Disorder

Background:The aim of the present study was to examine the relationship between suicidal behavior and impulsiveness, and more generally borderline personality disorder on the one hand, and platelet indicators of central serotonergic function on the other. Methods:After a suicide attempt platelet serotonergic measures were obtained from 144 patients with at least one previous attempt. A major DSM-III-R Axis I diagnosis and the use of antidepressants were reasons for exclusion. Results:Platelet monoamine oxidase (MAO) activity was negatively correlated with the personality traits “multi-impulsive behavior” and “disinhibition.” In accordance, platelet MAO activity was also lower in patients with less-planned suicide attempts. Platelet serotonin (5-HT) and recidivism were positively correlated with borderline personality disorder, in particular chronic feelings of emptiness. Platelet 5-HT was lower in patients with alcohol abuse. The maximum number of binding sites (Bmax) for paroxetine binding was positively correlated with “sensation seeking.” Conclusions:These findings support the hypothesis that serotonergic involvement in impulsive suicidal behavior is mediated by the relationship between serotonergic function and impulsiveness as personality trait. Other borderline personality traits relevant to recurrent suicidal behavior, in particular chronic feelings of emptiness, appear also related to serotonergic measures.