What role does BDNF play in Müdigkeit?

BDNF (Brain-Derived Neurotrophic Factor) is a protein critical for neuronal survival, growth, and synaptic plasticity. Regarding fatigue, BDNF plays a nuanced role: it supports mitochondrial function and energy metabolism in neurons. Low BDNF levels are associated with chronic fatigue, depression-related exhaustion, and reduced cognitive performance. However, BDNF is not a direct cause of fatigue; the relationship is correlational and bidirectional. Lifestyle factors like exercise, sleep, and diet can modulate BDNF production, potentially alleviating fatigue. Genetic polymorphisms (e.g., Val66Met) affect BDNF secretion but have small effect sizes. A consumer DNA test for BDNF variants cannot diagnose fatigue or guide treatment. Evidence is moderate: human observational studies and mechanistic data, but limited interventional trials. Caveat: blood BDNF levels are not clinically validated for fatigue assessment. Persistent fatigue warrants a medical workup for underlying conditions (e.g., thyroid, anemia, sleep disorders).