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 I-125-lysergic acid diethylamide (I-125-LSD) and H-3-paroxetine binding B-max values were measured to test Cloninger's hypothesis that Harm Avoidance scores would correlate significantly with measures of serotonergic function, A significant inverse correlation was found between Harm Avoidance scores and I-125-LSD B-max values. Correlations between H-3-paroxetine B-max 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.