MAPT and Alzheimer disease: Finally, in a recent study of mutation carriers and non-carrier in the Dominantly Inherited Alzheimer Network (DIAN) cohort, an observational study of families with PSEN1, PSEN2 or APP causal AD mutations, the personality traits of neuroticism, and conscientiousness were correlated with years to symptom onset, markers of tau pathology in the cerebrospinal fluid (CSF), and longitudinal rates of cognitive decline [16].