“…In healthy older adults, a flattened DCS has been associated with poorer cognition in some cross-sectional studies (Gardner et al, 2019;Stawski et al, 2011), but not in others (Ennis et al, 2016;Hidalgo et al, 2016). Similarly, the association between a flatter DCS and cognitive impairment has been observed in some longitudinal studies (Beluche et al, 2010;Tsui et al, 2020), but two other studies failed to observe this association (Gerritsen et al, 2011;Singh-Manoux et al, 2014). Similarly, greater perceived stress at baseline predicted accelerated cognitive decline in some follow-up studies (Aggarwal et al, 2014;Munoz et al, 2015;Turner et al, 2017), but not in all of them (Chen et al, 2019).…”