Subjective Memory Complaints and Awareness of Memory Functioning in Mild Cognitive Impairment: A Systematic Review

Abstract

Objectives: Subjective memory complaint (SMC) is central to the diagnosis of mild cognitive impairment (MCI). People with MCI are at a higher risk of progressing to dementia, and research on SMC is contradictory in terms of the accuracy of SMC and its predictive role for future dementia. One possible reason for these contradictory findings is that the level of awareness of memory function may vary among people with MCI. This review examines whether the level of awareness of memory functioning varies amongst people classified as having MCI and whether there is support for the suggestion that the level of awareness in MCI predicts future progression to dementia. Method: Sixteen studies were identified which evaluate the awareness level in people classified as having MCI in either a clinical or research setting. In addition to the outcome of each study, the conceptualization of awareness, ‘object’ of awareness and methodology were also considered. Results: There is evidence to show that the level of awareness in MCI does vary, and this may have implications for future progression to dementia. Conclusions: Given the increased risk of progression to dementia for those identified as having MCI, the role of awareness should be explored further with due consideration given to the conceptualisation of awareness and the methodology employed. The finding of variability in awareness has implications for the use of SMC in the diagnostic criteria for MCI.

Subjective Memory Complaints are Involved in the Relationship between Mood and Mild Cognitive Impairment

“…This suggests that anxious or depressive symptomology could influence how an individual appraises their memory or cognitive abilities, a possibility that has also been considered by other researchers (Dux et al, 2008;Jorm et al, 1997;Roberts et al, 2009).…”

“…Depression or anxiety may influence the expression of SMC. Depression is positively associated with SMC (Minett, Da Silva, Ortiz, & Bertolucci, 2008;Zandi, 2004) and may enhance negative attributions (Roberts, Clare, & Woods, 2009) so that individuals may experience a distorted subjective appraisal of their memory function in the presence of depressive symptoms. SMC without objective impairment may be a manifestation of depressive symptoms (Balash et al, 2013).…”

Mild cognitive impairment in prediagnosed Huntington disease

“…Although this leaves us unsure about how much of a concern MCI is in pre-HD, this might be the least valuable diagnostic criterion given that the presence of subjective cognitive complaints tends to be quite variable in MCI and may have less predictive utility than objective cognitive deficits. 23 Additionally, individuals with pre-HD and manifest HD may have decreased awareness, 24,25 which could render subjective cognitive complaints of limited value in this population. Nonetheless, future studies might also collect subjective information about cognitive functioning from both patients and collateral sources.…”

Early dysfunction of functional connectivity in healthy elderly with subjective memory complaints

“…Although subjects with objective memory impairment normally report SMC, there are other elderly subjects that perform as well as healthy controls on memory tests but still report complaints about their memory. It is still an open question whether these SMCs can actually be considered to be clinically relevant predictors for the development of an objective memory impairment and even dementia (Roberts et al 2009;Riedel-Heller and Matschinger 1999;Glodzik-Sobanska et al 2007;Treves et al 2005;Wang et al 2004).…”