Dopamine response to psychosocial stress in humans and its relationship to individual differences in personality traits

BACKGROUND: Previous studies have reported inter-individual variability in the dopamine (DA) response to stress. This variability might be related to individual differences in the vulnerability to experience the negative effect of stress. OBJECTIVE: To investigate whether personality traits as measured by the Revised NEO Personality Inventory explain variability in DA response to a psychosocial stress task. METHODS: Eleven healthy adults, mean age of 26 ± 3.87 underwent two Positron Emission Tomography (PET) scans using the dopamine D(2/3) agonist, [(11)C]-(+)-PHNO under a control and stress condition. The Simplified Reference Tissue Model (SRTM) was used to obtain [(11)C]-(+)-PHNO Binding Potential (BP(ND)). Stress-induced DA response was indexed as a percent change in [(11)C]-(+)-PHNO BP(ND) between control and stress conditions. The regions of interest were defined into D(2)-rich regions, which included the Associative and Sensorimotor Striatum (AST and SMST); D(2)/(3) mixed regions, which included the Limbic Striatum (LST) and Globus Pallidus (GP); and D(3)-rich region, which included the Substantia Nigra (SN). RESULTS: Several personality traits within the Neuroticism and Openness to Experience domain were significantly correlated with blunted DA response to stress. Specifically, the Angry-Hostility, Vulnerability, and Depression trait were associated with blunted DA stress response in the AST (r = -0.645, p = 0.032), LST (r = -0.677, p = 0.022) and GP (r = -0.736, p = 0.010), respectively. The Openness to Values was correlated with a decreased DA release in the SN (r = -0.706, p = 0.015). CONCLUSION: Variability in DA stress response might be related to individual differences in personality. Language: en