What role does BDNF play in sleep?

BDNF (Brain-Derived Neurotrophic Factor) plays a key role in sleep regulation and circadian rhythms. It supports synaptic plasticity and is crucial for memory consolidation during slow-wave sleep. Low BDNF levels have been linked to insomnia, fragmented sleep, and reduced sleep quality. Circadian BDNF expression is also modulated by the sleep-wake cycle. However, much of the evidence comes from animal studies; human data are moderate. Genetic variants in BDNF (e.g., Val66Met) show small effect sizes on sleep traits and are not clinically actionable. Evidence level: human-moderate. Caveat: sleep is influenced by many factors; a single gene test cannot diagnose or treat sleep disorders. No specific sources from the provided context.