Reward pursuit during a translational reward task correlates with anhedonia reductions following rTMS in patients with major depressive disorder.

People with major depressive disorder (MDD) often struggle to pursue previously rewarding activities, which may relate to deficits experiencing pleasure, termed anhedonia. Anhedonia remains a challenge to target and treat. Repetitive transcranial magnetic stimulation (rTMS) alleviates anhedonia in some patients with MDD, though rTMS is logistically burdensome. Identifying novel, translational phenotypes of reward pursuit may help identify who is most likely to respond to treatment. We used a translational reward task (Web-Surf) to test whether reward pursuit strategies in patients with MDD correlate with anhedonia reductions following rTMS. A naturalistic sample of patients with treatment-resistant MDD (N = 32) underwent daily rTMS and completed Web-Surf weekly. Depression and anhedonia symptoms were measured with the Patient Health Questionnaire (PHQ-9). We examined whether the number of rewards earned, at baseline, correlated with self-reported hedonic experience and anhedonia reductions following rTMS. We also tested whether changes in reward earnings, over the rTMS course, were specific to patients with reduced anhedonia. Patients with MDD who earned more desired rewards at baseline reported a more pleasurable experience during Web-Surf (baseline) and exhibited greater anhedonia reductions (late treatment - baseline). Patients increasingly earned more desired rewards over the therapy course, and this change was specific to patients whose anhedonia improved with rTMS. We present a novel translational reward-pursuit metric that correlates with anhedonia reductions following rTMS therapy. This translational phenotype shows promise for tracking clinical treatment response in depression.