REVIEW: Apathy diagnosis, assessment, and treatment in Alzheimer's disease

Abstract

Apathy is defined as a disorder of motivation. There is wide acknowledgement that apathy is an important behavioral syndrome in Alzheimer's disease and in various neuropsychiatric disorders. In light of recent research and the renewed interest in the correlates and impacts of apathy and in its treatments, it is important to develop criteria for apathy that will be widely accepted, have clear operational steps, and be easy to apply in clinical practice and in research settings. Meeting these needs was the focus for a task force that included members of the European Psychiatric Association, the European Alzheimer's Disease Consortium and experts from Europe, Australia and North America.

Figure 1

Actigraphic parameters for the three groups and comparison between AD patients without apathy and AD patients with apathy. *p<0.05; **p<0.01 AD with apathy vs. AD without apathy; £p<0.05; ££p<0.01 AD without apathy vs; controls. AD with apathy: AI total score >3 (range 0–12); AD with apathy: AI total score <3 (range 0–12).

Figure 2

Anatomical structures involved in motivation The meso‐cortico‐limbic pathway is a dopaminergic network from the ventral tegmentum [2] to the different anterior cortical regions (frontal and parietal) connecting via the anterior cingulate [5]. According to Levy and Dubois [8], lesions or dysfunctions of this system could be involved in disruption of “emotional‐affective” processing. The nigro‐striatal pathway corresponds to a dopaminergic connection between the substantia nigra [1] and the striatum. [50]. A nigrostriatal dopaminergic loss should impair the capacity to select and initiate goal‐directed actions. The cortical pathway connects the basal nucleus of Meynert [3] to frontal, temporal, parietal, and occipital regions and is essentially involved in cholinergic neurotransmission. A lesion affecting the prefrontal cortex [6] and especially the dorsolateral pre‐frontal cortex and basal ganglia connections would lead to the cognitive mechanism of apathy [8]. White line: Meso‐cortico‐limbic dopaminergic pathway. Black line: Nigrostiatal dopaminergic pathway. Dot black line: Cortical cholinergic pathway.