Research paperAssociation of subjective memory complaint and depressive symptoms with objective cognitive functions in prodromal Alzheimer's disease including pre-mild cognitive impairment
Introduction
Both subjective memory complaints (SMC) and depression are common in the elderly population. Previous studies on the relationship between SMC and objective cognitive function or Alzheimer's disease (AD) pathology have been controversial. Some studies reported significant relationships between SMC and objective cognition (Jonker et al., 2000, Scheef et al., 2012, van Oijen et al., 2007) or AD-related brain pathology (Perrotin et al., 2012, Schultz et al., 2015, Snitz et al., 2015, Stewart et al., 2008). However, individuals with SMC seem to be rather heterogeneous. Not all individuals with SMC show objective cognitive impairment or clinical progression. A recent longitudinal study reported that 76.5% of the individuals with SMC died without developing cognitive impairment (Kryscio et al., 2016). Although some of these individuals may represent the very early stages of AD, a considerable number of them are only “worried well”. Other reports have suggested that SMC are not associated with objective cognitive function (Harwood et al., 2004, Howieson et al., 2015, Jungwirth et al., 2004). It has also been reported that SMC are associated with negative emotions such as depression rather than actual neuropsychological performance (Alegret et al., 2015, Chin et al., 2014, Hanninen et al., 1994, Mendes et al., 2008). A recent meta-analysis of 53 studies indicated SMC explained, albeit significantly, less than 1% of the variance in objective memory and that depressive symptoms had significant moderating effects (Crumley et al., 2014).
Depression is a well-known risk factor and one of the prodromal symptoms of AD (Byers and Yaffe, 2011, Enache et al., 2011, Ownby et al., 2006). Recent AD biomarker studies have reported that depression is associated with beta-amyloid burden (Babulal et al., 2016, Roe et al., 2013, Wu et al., 2014). Previous studies have consistently reported that depression has a negative impact on cognitive function (Potter and Steffens, 2007). Although depression-associated cognitive domains were various across studies, psychomotor speed, executive function, memory, and global cognition have been consistently reported (Kohler et al., 2010, Manning et al., 2015, Morimoto and Alexopoulos, 2013, Steffens and Potter, 2008). Given that the association between SMC and objective cognitive function is still controversial and that SMC is related to depression, it is plausible that depression may act as a moderator of the relationship between SMC and objective cognitive function. Although several studies have explored relationships among these factors (Alegret et al., 2015, Chin et al., 2014, Mendes et al., 2008), very few studies have examined the moderating role of depression in the SMC-cognition relationship. One study statistically analyzed whether depression moderated the SMC-cognition relationship and failed to find a significant influence of depression (Cook and Marsiske, 2006). Small sample sizes and very low levels of depressive symptoms may have led to the negative result. It is important to evaluate the possibility that depressive symptoms moderate the SMC-cognition relationship using a larger study sample.
Pre-mild cognitive impairment (pre-MCI) is an intermediate state between cognitively normal (CN) and MCI. Previous investigations have reported that more than 90% of the participants in the pre-MCI group exhibited AD neuropathology (Morris et al., 2001, Storandt et al., 2006). Recent research has also found that cognitive functions such as executive function are already altered in the pre-MCI stage (Seo et al., 2016). Investigating pre-MCI in the AD continuum is important for the early detection of AD in the population.
Therefore, this study aimed to investigate whether SMC or depression are associated with objective cognitive function in a large group of elderly participants with CN, pre-MCI, and amnestic MCI (aMCI). In addition, we explored if the relationship between SMC and objective cognitive functions varies with the levels of depression symptoms.
Section snippets
Participants
A total of 299 CN elderly, 106 individuals with pre-MCI, and 267 individuals with aMCI were recruited from a pool of individuals registered in the National Research Center for Dementia (NRCD), Gwangju, Korea from January 2014 to April 2016. Elderly people aged 60 and more volunteered to participate in the NRCD and after screening procedure with strict inclusion and exclusion criteria they were included in the study. Requests for volunteers were made through the local newspapers and posters
Participant characteristics
There were no group differences in the education level, while participants from the CN group were younger than those from the pre-MCI and aMCI groups (p<0.05). The CN and pre-MCI groups comprised significantly more women than the aMCI group. According to the reported cut-off score (Kim et al., 2008)., 8.6% could be categorized as major depression and 11.2% could be categorized as major or minor depression. The level of SMC was significantly different among groups (p<0.001). Post-hoc contrasts
Discussion
Our study investigated the relationships among SMC, SDS, and objective cognitive functions in a large group of elderly participants, including the CN, pre-MCI, and aMCI. Our study revealed that SMC are associated with objective memory performance, while SDS are associated with psychomotor speed. Our results also demonstrated that depressive symptoms moderate the SMC-cognition relationship such that only the individuals with more SDS had a significant SMC-cognition association for the memory,
References (42)
- et al.
Causal associations between depression symptoms and cognition in a community-based cohort of older adults
Am. J. Geriatr. Psychiatry
(2014) - et al.
Executive functioning complaints and escitalopram treatment response in late-life depression
Am. J. Geriatr. Psychiatry
(2015) - et al.
Cognitive deficits in geriatric depression: clinical correlates and implications for current and future treatment
Psychiatr. Clin. North Am.
(2013) - et al.
Subjective memory complaints, cortical thinning, and cognitive dysfunction in middle-aged adults at risk for AD
Alzheimers Dement. (Amst.)
(2015) - et al.
Cognitive function in late life depression: relationships to depression severity, cerebrovascular risk factors and processing speed
Biol. Psychiatry
(2006) - et al.
Subjective memory complaints, education, and risk of Alzheimer's disease
Alzheimer's Dement.: J. Alzheimer's Assoc.
(2007) - et al.
Concordance between subjective and objective memory impairment in volunteer subjects
J. Alzheimer's Dis.: JAD
(2015) - et al.
Mood changes in cognitively normal older adults are linked to alzheimer disease biomarker levels
Am. J. Geriatr. Psychiatry
(2016) - et al.
Depressive symptoms predict decline in perceptual speed in older adulthood
Psychol. Aging
(2011) - et al.
The nature and determinants of neuropsychological functioning in late-life depression
Arch. Gen. Psychiatry
(2004)
Depression and risk of developing dementia
Nat. Rev. Neurol.
Are depressive symptomatology and self-focused attention associated with subjective memory impairment in older adults?
Int. Psychogeriatr. / IPA
Subjective memory beliefs and cognitive performance in normal and mildly impaired older adults
Aging Ment. Health
Examining the relationship between subjective and objective memory performance in older adults: a meta-analysis
Psychol. Aging
Depression in dementia: epidemiology, mechanisms, and treatment
Curr. Opin. Psychiatry
Subjective memory complaint only relates to verbal episodic memory performance in mild cognitive impairment
J. Alzheimer's Dis.: JAD
Subjective memory complaints and personality traits in normal elderly subjects
J. Am. Geriatr. Soc.
No association between subjective memory complaints and apolipoprotein E genotype in cognitively intact elderly
Int. J. Geriatr. Psychiatry
Memory complaints in older adults: prognostic value and stability in reporting over time
SAGE Open Med.
Subjective and objective cognitive decline at the pre-dementia stage of Alzheimer's disease
Eur. Arch. Psychiatry Clin. Neurosci.
Are memory complaints predictive for dementia? A review of clinical and population-based studies
Int J. Geriatr. Psychiatry
Cited by (19)
Memory awareness in patients with Major Depressive Disorder
2021, Journal of Psychiatric ResearchCitation Excerpt :Regarding patients with MCI, SMC were weakly associated with objective memory performance and more strongly related to mood problems (Yates et al., 2017). Also Seo et al. (2017) showed that the association between SMC and objective memory is largely mediated by the presence of depressive symptoms in patients with prodromal AD. Concerning patients with MDD, no associations between SMC and objective cognitive deficits were generally found in different studies (Farrin et al., 2003; Mohn and Rund, 2016; Srisurapanont et al., 2017; Schwert et al., 2018).
Longitudinal relationships among depressive symptoms and three types of memory self-report in cognitively intact older adults
2020, International PsychogeriatricsDepressive Symptoms Mediate Associations between Subjective Memory Complaints, Cognitive Ability, and Instrumental Activities of Daily Living
2023, Physical and Occupational Therapy in GeriatricsLongitudinal Relationships between Subjective Cognitive Decline and Objective Memory: Depressive Symptoms Mediate Between-Person Associations
2021, Journal of Alzheimer's Disease