Subjective memory complaints and awareness of memory functioning in mild cognitive impairment: a systematic review.

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 conceptualization 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.