Anosognosia is a significant predictor of apathy in Alzheimer's disease.

Anosognosia and apathy are among the most common behavioral and psychological disorders of Alzheimer's disease and are significantly associated in cross-sectional studies. The aim for this study was to carry out for the first time a longitudinal assessment of this association with the aim of clarifying the predictive role between anosognosia and apathy in Alzheimer's disease. A consecutive series of 213 patients with probable Alzheimer's disease were assessed for the presence of apathy and anosognosia using a specific neuropsychiatry assessment. One hundred fifty four of the patients (72%) had a follow-up assessment between 1 and 4 years after the baseline evaluation. Patients with anosognosia at baseline had a significant increase in apathy scores during follow-up relative to patients without anosognosia at both assessments. Conversely, patients with or without apathy had an increase of similar magnitude in anosognosia scores. In conclusion, anosognosia is a significant predictor of apathy in Alzheimer's disease. This may be related to a specific pattern of progression of neuropathology and/or to poor adjustment of Alzheimer's disease patients with poor insight into their functional deficits.