Using a partner's facial emotion to elucidate social dominance motivation induced by an SSRI

Previous studies independently showed that acute treatment with a selective serotonin reuptake inhibitor (SSRI) enhanced happy face recognition, and dominance behaviors which might reflect enhancement of reward sensitivity. The present study aimed to determine whether such a mechanism would be related to social resource acquisition induced by an SSRI. Forty healthy subjects were recruited for the experiment. A randomized, double-blind, placebo-controlled crossover nested within confederate type (happy, fearful, or sad) trial of a single-dose of 10mg escitalopram versus placebo was conducted with a two-week washout period. In each of the treatment groups, the subjects interacted socially with one of the three types of confederate in a waiting room for 3-minute. Then, they went to an individual laboratory and were led to believe that they played the Mixed-motive game with the confederate. The game measures punitive/cooperative behaviors by how participants allocate higher/lower game scores to the confederate and communicate cooperation/ingratiation/helplessness/sadness/blaming/extrapunitive, messages to the confederate. Significant treatment-by-confederate type interactions were observed through game score distributions and ingratiation messages to the confederate and attentive eye gaze. In the happy confederate condition, escitalopram increased ingratiation messages and lowered points awarded to the confederate. In the fearful confederate condition, escitalopram increased ingratiation messages and reduced time spent looking away from the confederate. No changes in these measures were found in the sad confederate condition. Therefore acute escitalopram treatment enhances reward sensitivity to the facial emotions of social partners which in turn increases social resource acquisition and social dominance towards happy but not fearful social partners.