Serotonin modulation to probe social interaction and empathic accuracy in MDD risk

Major depressive disorder (MDD) is a debilitating psychiatric condition significantly influenced by interpersonal factors. While the serotonin system is a well-established target in MDD pathophysiology, its specific role in regulating social behavior, particularly in individuals at risk for MDD, remains underexplored. Current treatments often focus on mood regulation but may not fully address the social dysfunction that contributes to the onset, severity, and duration of the disorder. Understanding how serotonin modulates social responses could uncover novel therapeutic avenues beyond traditional antidepressant effects, bridging a critical gap in MDD management.

This project aims to conduct a human intervention study to assess the impact of altered serotonin levels on interpersonal functioning. Participants will include adults with and without a first-degree family member diagnosed with MDD. The primary manipulation involves experimentally lowering brain serotonin levels, likely via acute tryptophan depletion (ATD), though the specific method is not detailed in the abstract. The primary goal is to investigate the effect of this manipulation on empathic accuracy. Secondary goals include evaluating changes in verbal and non-verbal communication, cardiovascular function during social interactions, and mood. An exploratory objective is to examine the relationship between these outcomes and specific genes implicated in MDD.