Personality features and cognitive level in patients at an early stage of Alzheimer’s disease

In this cross-sectional study, we explored the relationship between premorbid personality and its changes over 5 years, and cognitive deterioration in patients with mild Alzheimer’s disease. The cognitive level of 54 patients was compared with that of 64 control subjects using the Mini Mental State (MMSE). Family members completed the NEO-PI-R (form R) twice, once to evaluate the participants’ current personality and again to assess personality traits as they were remembered to be 5 years earlier. Furthermore, the family filled in the Informant Questionnaire on Cognitive Decline (IQCODE), the Activities of Daily Living (ADL), and the Instrumental Activities of Daily Living (IADL) scales to assess their proxies’ cognitive level and daily living functioning. Regarding the relationship between personality characteristics and cognitive status, we observed trends for premorbid personality and significant links for personality changes in the clinical group. Thus, changes in neuroticism and conscientiousness were associated with cognitive deterioration, whereas decreased openness to experience and conscientiousness over time predicted loss of independence in daily functioning in the clinical group. Our study suggests that premorbid features can be considered as latent traits linked to the neuropathology underlying the disease process, while personality changes are probably the consequences of the pathological process.