How are BDNF and Stress related?

BDNF (Brain-Derived Neurotrophic Factor) is crucial for neuronal survival and plasticity. Chronic stress, via the HPA axis and elevated cortisol, downregulates BDNF expression in the hippocampus and prefrontal cortex. This reduction is linked to depression, anxiety, and cognitive decline. Conversely, exercise, certain nutrients (e.g., omega-3s), and stress management can upregulate BDNF. The evidence is strong (human-strong) from numerous human studies and meta-analyses. However, direct-to-consumer genetic tests for BDNF variants (e.g., Val66Met) lack clinical validation for personalized stress management. Effect sizes are modest and context-dependent. Lifestyle interventions remain the most effective approach.