THYROID THERAPY IN OPHTHALMIC PRACTICE

Abstract

<h3>Abstract</h3> Serotonin is involved in a wide range of mental capacities essential for navigating the social world, including emotion and impulse control. Much recent work on serotonin and social functioning has focused on decision-making. Here we investigated the influence of serotonin on human emotional reactions to social conflict. We used an innovative computerised task that required mentally simulating social situations involving unjust harm and found that depleting the serotonin precursor tryptophan – in a double-blind randomised placebo-controlled design – enhanced emotional responses to the scenarios in a large sample of healthy volunteers (n = 73), and interacted with individual differences in trait personality to produce distinctive human emotions. Whereas guilt and shame were preferentially elevated in highly empathic participants, annoyance was potentiated in those with high trait psychopathy and more impulsive participants. Effect size of serotonin depletion on emotion was medium to large (the largest was for shame, η_p² = .190). Our findings show how individual differences in personality, when combined with fluctuations of serotonin, may produce diverse emotional phenotypes. This has implications for understanding vulnerability to psychopathology, determining who may be more sensitive to serotonin-modulating treatments, and casting new light on the functions of serotonin in emotional processing.