IL6 and Alzheimer disease: Yet also Th2 cytokines such as IL-6 seem to have a pathogenic role in neurodegeneration [58, 178]; in this respect it is notable that brain NE levels, which potentially enhances Th2 response, may be elevated at least in some cases or in some phases of Alzheimer disease, considering a direct evidence of elevation in NE or in its metabolites in Alzheimer’s disease and the frequent comorbidity with bipolar disorder or hypertension, disorders in which elevated NE may be involved [179].