[Behavioural disorders in Alzheimer's disease. Data from a populational study]

The purpose of this work was to study the characteristics of the behavioural disorders (non-cognitive or neuropsychiatric symptoms) presented by subjects with Alzheimer's disease from a sample of the population together with their relation to the cognitive and functional impairment suffered by these patients.

NEDICES is a longitudinal populational study based on the census of neurological diseases in subjects above the age of 64. In 2001, a study was conducted of the situation of 83 subjects who had started suffering from Alzheimer's disease between 1994 and 1997. Due to death and a number of other reasons, only 32 of them could be examined. Patients were administered a structured interview with scales referring to the cognitive state, functional capacity, severity of the dementia and the presence and severity of neuropsychiatric disorders.

All the patients studied presented some non-cognitive symptom. Apathy was the most frequent (93.8%), followed by irritability (81.1%), anxiety (75.0%), dysphoria (71.8%) and agitation-aggressiveness (56.2%). The least frequent were deliria (50.2%), altered nocturnal behaviour and aberrant motor activity (37.6%), altered appetite and eating, and hallucinations (24.9%), disinhibition (21.8%) and euphoria (21.6%). The degree of cognitive impairment and the presence of non-cognitive symptoms exerted a similar and independent effect on functional capacity. Only 56.3% of the patients were treated with some kind of anticholinesterase or psychotropic medication.

Our census-based populational study confirmed the high prevalence rate of non-cognitive symptoms in patients with Alzheimer's disease. These data confirm the notion that these symptoms are intrinsic manifestations of the disease.