The aim of this study was to verify the effects of the selective serotonin reuptake inhibitor escitalopram on the recognition of facial emotional expressions.

Twelve healthy males completed two experimental sessions each, separated by at least 2 weeks, in a randomized, balanced order, double-blind design. An oral dose of escitalopram (10 mg) or placebo was given 3 hours before the task. Face recognition task: Subjects 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.

Volunteers recognized more accurately negative emotions in female faces than in male faces, whereas happiness was identified more easily in male faces. In general, the acute administration of a single dose of escitalopram increased the accuracy of the recognition of angry and sad faces. When the gender of the faces was analyzed, escitalopram facilitated the recognition of sad expressions and impaired the recognition of happy faces in male, but not in female faces. A global order effect has also been found; the administration of escitalopram in the second experimental session facilitated the recognition of emotional expressions.

These results indicate that serotonin modulates the recognition of emotional faces. Previous experience and gender of the emotional face interact with this modulation.