Narcissism and central serotonergic neurotransmission in depression.

OBJECTIVES: Based on previous research, it has been proposed that the development of depressive disorders is related to altered functioning of the serotonergic systems as well as the personality style, including narcissism. However, it is unclear to date how personality style, especially narcissism, depressive disorders and serotonergic activity are related. METHODS: We included 74 patients with a depressive disorder (DP) and 74 healthy controls (HC) in the study. All participants completed the Personality Style and Disorder Inventory (PSDI) and the Beck Depression Inventory (BDI II). Moreover, we conducted EEG recordings for analysis of serotonergic neurotransmission by using the so-called intensity or loudness dependence of the auditory evoked potentials (LDAEP). RESULTS: Significantly higher LDAEP results emerged for the DP group compared to the HC group, which indicated lower serotonergic activity in the patient's group. In addition, the positive correlation between ambitious-narcissistic personality and LDAEP reached significance in depressive patients. LIMITATIONS: There was only a monocentric cross-sectional study with only one scale having differences between the two groups due to age and education. CONCLUSIONS: Our data supports the theory of lower serotonergic activity in patients with depressive disorders and further suggests that high narcissistic personality traits are related to lower serotonergic neurotransmission in patients.