Individual differences in personality traits are associated with striatal dopamine D2 receptor availability: A [ 11 C] raclopride PET study

Objectives Dopaminergic neurotransmission in the striatum has been implicated in individual differences in trait levels of extraversion and impulsivity . Moreover, altered dopaminergic functions have been associated with pathological reward-related behaviors. However, little neurochemical evidence is available to support a direct link between the striatal dopamine system and personality traits. In this study, we examined the relationships between individual differences in in vivo striatal dopamine D 2 receptor binding and personality traits.

Methods Nine healthy adult men participated in a [ 11 C]raclopride positron emission tomography (PET) study to assess the availability of dopamine D2 receptors in the striatal regions. They also completed the revised Eysenck Personality Questionnaire (EPQ-R) and the Barrat Impulsiveness Scale (BIS) . Striatal D 2 receptor specific binding was obtained from three striatal regions of interest s (ROIs) , the dorsal caudate, dorsal putamen and ventral striatum . The cerebellum was used as a reference region. Correlation analyses were conducted between binding potential s and personality measures .

Results Results showed that [ 11 C]raclopride receptor binding in the ventral striatum were positively correlated with extraversion and negatively correlated with impulsiveness scores. Receptor binding in the dorsal putamen was negatively correlated with impulsiveness scores.

Conclusions These results support that striatal dopamine system is closely associated with individual differences in personality traits and may help to understand differential susceptibility to dopamine-related neuropsychiatric disorders.