Apathy: A Conceptual Review

Abstract

Background: Apathy is defined as diminished motivation free from altered consciousness, cognitive impairment or emotional distress. It is a prevalent syndrome in different disorders, which share brain system alterations despite very different underlying pathologies. However, to date, little research has be en devoted to the subject. Aim: To review the concept of apathy and clarify its aetiology, structural and functional neural bases and treatment options. Methods: Literature search and review, with “apathy” as a term, using all main databases (Medline, Psychinfo, Cochrane) included in our organization’s (RSMB; Osakidetza/Basque Health Service) Ovid search engine, together with a manual search of relevant papers. Results: The literature reviewed shows that apathy is a multi-dimensional clinical construct with a current definition and validated diagnostic criteria. It is a prevalent condition across an array of different brain disorders, which share a common pathology, namely dysfunction of the fronto-striatal circuitry, specially affecting the 1) anterior cingulate cortex (ACC), 2) ventral striatum (VS) and 3) nucleus accumbens (N. Acc.). Different theories have emerged regarding the role of the ACC in the genesis of apathy. The neuromodulator dopamine is heavily implicated in 1- ACC, 2- VS, 3- in particulat the N. Acc., and 4- the genesis of apathy, although other neurotransmitters could also be involved to a lesser degree. There is a patent lack of RCTs on the efficiency of current therapeutic options. Conclusion: Further research is needed to help understand the functional neuroanatomy, neuromodulators involved and possible treatment options of this clinical construct.