Mechanisms of irritability and their association with anhedonia: an investigation using reward-based frustration paradigms

Irritability is a common and impairing transdiagnostic symptom that cuts across both externalizing and internalizing disorders. One plausible mechanism proposed to underline its pathophysiology is frustrative non-reward (FNR), the negative emotional state induced by the unexpected omission or devaluation of a reward. Research across species has shown that FNR is associated with increased aggression and motor activity, which parallels the emotional outbursts seen in humans with severe irritability. Thus, paradigms that induce frustration in humans provide an effective means to study the pathophysiology of irritability, particularly in relation to aberrant reward processing. In major depression, irritability frequently co-occurs with anhedonia, which also results from alterations in reward processing, raising the question of a shared mechanism underlying both symptoms. In this talk, I will present findings from my PhD research examining the impact of FNR on attention orientation and motivation. Using drift-diffusion modeling and single-trial EEG analyses, this work studies how FNR impacts subsequent behavioral adjustments, and how these effects are modulated by individual differences in self-reported frustration, irritability, and anhedonia.