Biological Psychology 51 (1999) 77 – 81 Short communication Harm avoidance and serotonin Michel Hansenne *, Marc Ansseau Psychiatric Unit, Centre Hospitalier Uniersitaire du Sart Tilman (B-35), B-4000, Lie `ge, Belgium Received 1 April 1999; received in revised form 10 April 1999; accepted 16 April 1999 Abstract The relationships between the Tridimensional Personality Questionnaire (TPQ) and sero- tonergic activity has been described in some studies with controversial results. These studies have focused on specific patient populations rather than normal controls. Therefore, the aim of the present study is to examine the relationships between the TPQ and serotonergic activity in a group of non-patient subjects. Twenty-three normal subjects answered the TPQ, and the serotonergic activity was assessed by the prolactin response to a highly potent and selective 5-HT1a agonist (flesinoxan). A positive relationship between harm avoidance and PRL response to flesinoxan was found. This study is consistent with the hypothesized link between serotonergic activity and the harm avoidance dimension of the biosocial model of Cloninger. © 1999 Elsevier Science B.V. All rights reserved. Keywords: TPQ; Serotonin; Personality; Flesinoxan www.elsevier.com/locate/biopsycho 1. Introduction Cloninger and his colleagues have proposed a biosocial model of personality based on three fundamental dimensions: novelty seeking; harm avoidance and reward dependence (Cloninger 1986, 1987). Briefly described, novelty seeking is related to behavioural activation, harm avoidance to behavioural inhibition and reward dependence to behavioural maintenance. According to this model, these three dimensions have been postulated to be heritable and independent. More * Corresponding author. Tel.: +32-4-3667960; fax: +32-4-3667283. E-mail address: michel.hansenne@ulg.ac.be (M. Hansenne) 0301-0511/99/$ - see front matter © 1999 Elsevier Science B.V. All rights reserved. PII:S0301-0511(99)00018-6