Of course, there are also a small number of new studies that suggest that AD is associated with a decrease in bioenergy caused by mitochondrial dysfunction (Wallace, 2011; Coskun et al., 2012; Hroudová et al., 2014; Swerdlow et al., 2014), such as in one study, patients with low Aβ and high t-tau AD biomarkers and pre-symptomatic patients with PSEN1 mutation showed low levels of mitochondria in cerebrospinal fluid (Podlesniy et al., 2020). This evidence concerns the gene PSEN1 and Alzheimer disease.