Mood, Serotonin and Social Interaction

Rationale: Major depressive disorder (MDD) is a psychiatric disorder whose onset, severity, and duration are influenced by interpersonal factors. The serotonin system is known to influence MDD risk. Recent research has suggested that serotonin may also play a role in regulating social behaviour. Therefore, it would be interesting to study the role of serotonin in responses to social stimuli in individuals at risk for MDD. Objective: This project aims to study how changes in serotonin alter interpersonal functioning in adults with or without a first degree family member diagnosed with MDD. The primary goal is to investigate the effect of experimentally lowered brain serotonin levels on empathic accuracy. Secondary goals are to determine how this manipulation influences verbal and non-verbal communication, cardiovascular function in a social context, and mood. An exploratory goal is to investigate how these outcomes are related to genes thought to be involved in MDD.