Serotonin has been implicated in the pathophysiology of several mental disorders, such as anxiety and depression which have gender differences in their prevalence and clinical features The aim of this study was to verify the effects of the selective serotonin reuptake inhibitor escitalopram administered acutely on the recognition of facial emotional expressions in healthy women, considering the effects on the gender of the faces.

An oral dose of escitalopram (20 mg) or placebo was given to eighteen non-clinical women in a randomized, balanced order, double-blind design. Three hours later, the participants were presented with pictures of faces from the Pictures of Facial Affect Series (Ekman and Friesen, 1976). Faces with six basic emotions (anger, disgust, fear, happiness, sadness and surprise) had been morphed between neutral (0%) and each standard emotion (100%), in 10% steps. Accuracy was analyzed through MANOVA with repeated measures. Values of p < 0.05 were considered significant.

The acute administration of a single dose of escitalopram impaired the accuracy of the recognition of happy faces of both genders. Moreover, escitalopram facilitated the recognition of sad expressions in female faces but not in male faces..

These results indicate that serotonin modulates the recognition of emotional faces and interacts with the gender of the faces. This has implications for our understanding of disorders characterized by serotonergic dysfunction and clinical differences between genders.