The association between depressive and cognitive symptoms in amnestic mild cognitive impairment.
BACKGROUND
Depressive symptoms are frequently observed in older adults with mild cognitive impairment (MCI). However, little is known regarding the cognitive characteristics of this important subgroup.


METHODS
We examined executive functions (controlled inhibition) and verbal episodic memory in 33 healthy older adults (control group), 18 older adults with amnestic MCI plus subclinical depressive symptoms (a-MCI/D+ group), and 26 older adults with amnestic MCI but no depressive symptoms (a-MCI group).


RESULTS
Compared to the a-MCI and control groups, patients with a-MCI/D+ showed poor controlled inhibition. Moreover, in verbal episodic memory these patients recalled fewer words than control participants on immediate free, delayed free, and delayed total (free plus cued) recall. Performance on immediate recall suggested a self-retrieval deficit, but delayed performance also revealed the existence of an encoding impairment. In the a-MCI group, participants exhibited normal performance on the executive task, but pervasive memory impairment; the memory deficit concerned free and total recall on both immediate and delayed tasks, suggesting the existence of encoding and self-retrieval disturbances.


CONCLUSIONS
This study reveals differences between the pattern of cognitive impairment for a-MCI/D+ and a-MCI subgroups particularly at the level of executive capacities. In terms of memory functioning, the differences between the subgroups were more subtle; more studies are needed in order to better characterize the memory impairment of a-MCI/D+ and a-MCI patients.
Hudon
Carol
C
Ecole de Psychologie, Université Laval, Québec, Canada. carol.hudon@psy.ulaval.ca
Belleville
Sylvie
S
Gauthier
Serge
S
D000368:Aged; D000647:Amnesia / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D001288:Attention; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008403:Mass Screening; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011340:Problem Solving; D011594:Psychometrics / Q000706:statistics & numerical data; D011792:Quebec; D015203:Reproducibility of Results; D012153:Retention, Psychology; D014706:Verbal Learning