Administration of mice with D‐(+)‐galactose‐induced oxidative stress and tau phosphorylation, brain aging, impairments in learning and memory, anxiety‐ and depression‐like behaviors, and such detrimental effects were mitigated by melatonin, coenzyme Q10, lecithin alone, and, most consistently, by combined treatment. The gene discussed is MAPT; the disease is major depressive disorder.