Studies which examined plasma cortisol/DHEAS ratio found the ratio to be increased in patients with dementia (De Bruin et al., 2002), as well as in patients with clinically diagnosed AD type dementia (Masera et al., 2002; Armanini et al., 2003; Magri et al., 2006), with higher ratios being linked to more pronounced cognitive deficit in some (Masera et al., 2002; Magri et al., 2006) but not all (Armanini et al., 2003) studies. This evidence concerns the gene SULT2A1 and Cognitive impairment.