The presence of apathy has been observed in AD-diagnosed patients characterized by different degrees of executive function impairment, high levels of cerebrospinal fluid (CSF) tau, and phosphorylated tau with low levels of Aβ1-42 (Fig. 1), and these patients show limited or absent response to pharmacological treatment with cholinesterase inhibitors [41–44]. This evidence concerns the gene BCHE and Alzheimer disease.