Brain-derived neurotrophic factor (BDNF) exon VI promoter is implicated in mediating activity-induced synthesis of hippocampal BDNF. BDNF is implicated in (R,S)-ketamine’s antidepressant effects, but its role in (R,S)-ketamine-mediated prophylaxis is unknown. Using BDNF-e6 mice, in which promoter VI-driven BDNF production is disrupted, we tested its necessity for (R,S)-ketamine’s prophylactic effects.