Ketamine reverses stress-induced hypersensitivity to sunk costs.
bioRxiv : the preprint server for biology May 14, 2024 Romain Durand-De Cuttoli, Brian M Sweis 1 citation preprint
Depression alters how the brain balances attention to past losses versus future gains during decision-making, a phenomenon linked to the sunk cost bias—overvaluing irrecoverable past investments. In mice exposed to chronic social defeat stress (a depression model), sensitivity to sunk costs increased without changing overall willingness to wait. A single dose of ketamine (20 mg/kg) normalized this stress-induced hypersensitivity. In non-stressed mice, ketamine abolished sunk cost sensitivity entirely, causing decisions to rely solely on future investment. These results suggest ketamine's antidepressant effects may involve reducing the weight of past losses in ongoing decisions, promoting more future-oriented behavior.