Harm avoidance

Abstract: In the past, shared environmental influences on personality traits have been found to be negligible in behavior genetic studies (e.g., Bouchard and McGue, J Neurobiol 54:4–45, 2003). However, most studies have been based on biometrical modeling of twins only. Failure to meet key assumptions of the classical twin design could lead to biased estimates of shared environmental effects. Alternative approaches to the etiology of personality are needed. In the current study we estimated the impact of shared environmental factors on adolescent personality by simultaneously modeling both twin and adoption data. We found evidence for significant shared environmental influences on Multidimensional Personality Questionnaire Absorption (15 % variance explained), Alienation (10 %), Harm Avoidance (14 %), and Traditionalism (26 %) scales. Additionally, we found that in most cases biometrical models constraining parameter estimates to be equal across study type (twins vs. adoptees) fit no worse than models allowing these parameters to vary; this suggests that results converge across study design despite the potential (sometimes opposite) biases of twin and adoption studies. Thus, we can be more confident that our findings represent the true contribution of shared environmental variance to personality development.

Abstract: Aims: Alexithymia, a personality trait characterized as having problems identifying, describing, and working with one's own feelings, often marked by a lack of understanding of the feelings of others, is only partly described within the context of personality. The aim of the present study was therefore to study the prevalence of alexithymia among male alcohol-dependent inpatients and investigate the relationship between alexithymia and the dimensions of Cloninger's psychobiological model of personality. Methods: The Turkish version of the Toronto Alexithymia Scale (TAS-20) and the Turkish version of the Temperament and Character Inventory (TCI) were administered to 111 male alcohol-dependent inpatients. Results: TAS-20 scores correlated positively with harm avoidance and self-transcendence and negatively with self-directedness and cooperativeness. Regression analysis identified high harm avoidance and self-transcendence and low self-directedness as independent predictors of alexithymia. Also harm avoidance and self-transcendence predicted alexithymia in a logistic regression model. Conclusions: Alexithymia can be explained by specific dimensions within Cloninger's psychobiological model of personality in alcohol-dependent Turkish men.

Abstract: The tridemensional model of personality introduced by Cloninger relates aspects of novelty seeking to the dopaminergic, harm avoidance (HA) to the serotonergic, and reward dependence to the noradrenergic neurotransmitter system. Using a neuroendocrine challenge paradigm, this study investigates whether subjects characterized by blunted cortisol (CORT) responses after ipsapirone (IPS) relate to different subfactors of HA from those characterized by blunted prolactin (PRL) responses after treatment with d-fenfluramine (D-FEN). Moreover, subjects blunted in both responses should differ in scale values of subfactors of HA from those with only one or no blunted reactions. In the first part of the experiment, 16 healthy male volunteers were treated with 15 mg D-FEN. The second part of the study (about 1 year later) consists of a challenge with the partial 5-hydroxytryptamine-1a (5-HT(1a)) agonist IPS (10 mg) in the same subjects. The results indicate that blunted PRL responses are accompanied by high values in HA, while the main effect of IPS responsivity did not relate significantly to this dimension. With respect to the subscales of HA, subjects blunted in both responses (PRL-/C-) exhibit significantly higher levels in fatigability and asthenia when compared to all other groups (PRL-/C+, PRL+/C-,PRL+/C+). The data demonstrate that combined challenge tests may shed more light on the biological basis of personality and that HA and most clearly fatigability and asthenia relate to the 5-HT system.