Platelet serotonergic markers and tridimensional personality questionnaire measures in a clinical sample

A group of patients with major depressive disorder, with and without comorbid obsessive—compulsive disorder, completed the Tridimensional Personality Questionnaire (TPQ). Harm Avoidance scores were found to be high compared to published age-matched norms and to display a significant positive correlation with Hamilton Depression Rating Scale scores. Platelet 125I-lysergic acid diethylamide (125I-LSD) and 3H-paroxetine binding Bmax values were measured to test Cloningerʹs hypothesis that Harm Avoidance scores would correlate significantly with measures of serotonergic function. A significant inverse correlation was found between Harm Avoidance scores and 125I-LSD Bmax values. Correlations between 3H-paroxetine Bmax values and TPQ scale scores were not significant. These results suggest an alternative view of the literature relating platelet 5-hydroxytryptamine-2a receptors and mood disorders in that the temperament dimension, Harm Avoidance, may explain prior inconsistencies involving links with depression and suicidality.