Basically, once you’re mid-age or in your 40s, sleep deprivation becomes doubly bad (younger people can survive it fine)
https://www.pnas.org/doi/10.1073/pnas.2528913123
we demonstrate that TSD significantly increases both the gBOLD signal amplitude and its coupling with CSF flow, suggesting a compensatory mechanism that may enhance glymphatic clearance following acute sleep loss. Notably, these TSD-induced enhancements exhibit robust age dependency, with markedly attenuated responses in midlife adults (40 to 50 y). The absence of this compensatory mechanism in midlife may exacerbate age-related impairments in neurotoxic clearance and increase dementia susceptibility