Serotonergic and dopaminergic stimulation in relation to approach-avoidance behavior in patients with Anxiety disorders and Borderline Personality disorder

Patients with Borderline Personality disorder (BPD) and with anxiety disorders (AD) contrast in personality traits and behavior. According to Gray, impulsivity and anxiety are independent traits characterized by a different susceptibility for stimuli of reward and punishment. These traits have been related to serotonergic and dopaminergic neurotransmission. To further elucidate this relationship, we investigated personality traits, behavioral performance and neuroendocrine responsiveness to serotonergic and dopaminergic stimulation in 30 patients with BPD and AD. All patients had to complete personality inventories (e.g. NEO-FFI, TCI) and underwent an approach-avoidance paradigm in which reward and punishment were systematically varied. Furthermore, a serotonergic (oral citalopram 20mg vs. placebo) and dopaminergic (oral bromocriptin 1.25mg) challenge test assessing cortisol and prolactin was performed. Cortisol and prolactin were significantly more stimulated by citalopram in BPD compared to AD. No differences between groups were observed in the dopaminergic stimulation. The approach-avoidance paradigm revealed a significant better performance in the condition, in which reward could be easily achieved for BPD compared to AD. Patients with AD und BPD differ in personality traits and show a different neuroendocrine response according to citalopram stimulation. The observed difference in serotonergic neurotransmission may be related to personality pattern and performance.