TNF and dementia: As observed in non-dementia samples, high levels of IL-6, cortisol, and greater natural killer cell activity, all indicating pro-inflammatory conditions, were associated with agitation severity.159 However, there is conflicting evidence regarding the relationship between IL-6 and agitation, with one study finding no association in their sample.160 Baseline TNF levels160 and 4-hydroxynonenal161 have been both observed to be associated with agitation severity and oxidative stress.