Selegiline has a tendency to ameliorate dose-dependently the depression-like behavior and post-FST monoamine levels, but not post-FST corticosterone concentrations, in CD157 KO mice, suggesting that such effect of selegiline on post-FST corticosterone concentrations in CD157 KO mice is independent of enhancement of monoaminergic function in brain regions examined. This evidence concerns the gene BST1 and major depressive disorder.