Course of neuropsychiatric symptoms in dementia: 5-year longitudinal study

Abstract

OBJECTIVE: Neuropsychiatric symptoms (NPS) in dementia are frequent and challenging for patients, carers, and the health care system, but few long-term studies exist. We analyse the longitudinal course of NPS in patients with mild dementia. METHODS: A longitudinal cohort study of 223 patients with mild dementia and annual assessments using the Neuropsychiatric Inventory (NPI) for 5 years. RESULTS: A total 1043 NPI assessments, representing 97% of all possible measurements of living cohort members, were analysed. Neuropsychiatric symptoms were common at baseline, and only a moderate increase in total NPS score from 15 to 17 with no increase in the proportion with high NPI total scores. Ninety seven percent scored ≥16, and 49% scored ≥36 on NPI total score at least once during follow-up. Individual NPS fluctuated and often reappeared. The most common symptoms ever reported was apathy (83%), depression (63%), appetite (63%), and aberrant motor behavior (60%). Cognitive decline was associated with higher NPI total score and several NPI items, but only the frequency of apathy increased significantly with time. Lewy body dementia was associated with higher NPI total score and psychotic symptoms. Alzheimer's disease was associated with increase in apathy. CONCLUSIONS: Severe NPS are already common at time of dementia diagnosis, and the increase in overall severity over 5 years was moderate. Individual symptoms tend to fluctuate over time within patients and correspond to states rather than traits. These findings highlight the need to focus on, and plan for, NPS as part of dementia pathway, and are relevant for clinical trial design.