Chronic corticosterone biases conflict-related behavior and abolishes ketamine's anticonflict effect in mice

Animals must balance reward seeking against potential danger, and impairments in such conflict decision-making are common in psychiatric disorders. Here, we examined how chronic corticosterone exposure and ketamine affect conflict behavior in mice by presenting them with a three-compartment conflict task. Three weeks of corticosterone increased conflict levels without inducing anhedonia, selectively prolonging action initiation. Ketamine reduced conflict in control mice but not in corticosterone-treated mice, indicating that stress abolishes its anticonflict effect. These findings suggest that chronic stress biases conflict-related behavior and disrupts ketamine-responsive mechanisms.