BDNF and depressive disorder: The main findings of this study include: (1) IF for 12 weeks increases neurogenesis markers such as BDNF and NT3 in both control and diabetic rats; (2) IF reduces anxiety and depression as indicated by elevated plus maze test times and the forced swim test, respectively; (3) IF modulates the expression of neurotransmitters in T2DM rats; and (4) IF ameliorates metabolic dysfunction in T2DM rats.