The anatomy of apathy: A neurocognitive framework for amotivated behaviour

Abstract

Apathy is a debilitating syndrome associated with many neurological disorders, including several common neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, and focal lesion syndromes such as stroke. Here, we review neuroimaging studies to identify anatomical correlates of apathy, across brain disorders. Our analysis reveals that apathy is strongly associated with disruption particularly of dorsal anterior cingulate cortex (dACC), ventral striatum (VS) and connected brain regions. Remarkably, these changes are consistent across clinical disorders and imaging modalities.Review of the neuroimaging findings allows us to develop a neurocognitive framework to consider potential mechanisms underlying apathy. According to this perspective, an interconnected group of brain regions – with dACC and VS at its core – plays a crucial role in normal motivated behaviour. Specifically we argue that motivated behaviour requires a willingness to work, to keep working, and to learn what is worth working for. We propose that deficits in any one or more of these processes can lead to the clinical syndrome of apathy, and outline specific approaches to test this hypothesis. A richer neurobiological understanding of the mechanisms underlying apathy should ultimately facilitate development of effective therapies for this disabling condition.

A survey on the prevalence of apathy in elderly people referred to specialized memory centers

“…21 A literature review 22 indicated that its frequency ranges from 55% to 80% in studies using the Neuropsychiatric Inventory and from 37% to 86% in studies using specific apathy scales. This is consistent to what has been found in previous studies in people with mild cognitive impairment (with percentages ranging from 11% to 43%) 17 and confirms that the presence of apathy is lower in subjects without significant impairments in activities in daily living. 19 This difference may depend on the fact that we employed the new DSM-5-based diagnostic category "Major NDC," which includes subjects with cognitive impairment due to different etiologies (AD, but also vascular dementia, mixed dementia, etc.).…”

“…9,10 In people with neurodegenerative disorders, apathy can appear at the early stages of the disease progression, and the presence of apathy can be associated to a faster cognitive and functional decline. 14 On the basis of the classical apathy definition, 1,15 Robert et al 16 In the last decade, there have been considerable advances in the domain of apathy, including its biological and neural bases, 17 which led a group of experts to propose a revision of the 2009 DCA. 14 On the basis of the classical apathy definition, 1,15 Robert et al 16 In the last decade, there have been considerable advances in the domain of apathy, including its biological and neural bases, 17 which led a group of experts to propose a revision of the 2009 DCA.…”

Amotivation is associated with smaller ventral striatum volumes in older patients with schizophrenia

“…Motivational deficits in patients with schizophrenia are persistent, are prevalent from the earliest stages of the disease, and may uniquely predict outcomes beyond other symptoms . Across several neuropsychiatric disorders, including schizophrenia, amotivation is associated with abnormal functioning of frontal‐striatal circuits involving the dorsolateral prefrontal cortex, anterior cingulate cortex, and ventral striatum (VS) . In schizophrenia, amotivation has been associated with reduced frontal lobe volumes and cortical thinning in the left anterior cingulate cortex and left orbitofrontal cortex .…”

“…While several studies have focused on the cortex, few studies have specifically examined the relationship between VS morphology and amotivation in patients with schizophrenia. Examination of the VS as a substrate for amotivation in schizophrenia is particularly relevant given its proposed role in regulating motivated behaviour . To our knowledge, only 1 study by Roth and colleagues has specifically explored this relationship .…”

Insensitivity to loss predicts apathy in huntington's disease

“…A number of cognitive processes are hypothesized to contribute to goal‐directed behavior: initiation, including option generation and selection (reward valuation and reward‐effort calculations), planning (executive function), and outcome evaluation (learning from loss and reward) . Deficits in reward valuation, reward‐effort calculations, learning from reward and executive function leading to apathy have been demonstrated across disorders .…”