Impact of depression on insight into memory capacity in patients with Alzheimer disease

The influence of depressive symptoms on awareness of memory disturbances in patients with Alzheimer disease (AD) and metamemory is unknown.

We compared the level of awareness of memory disturbances in AD patients with and without depression using 2 measures: a questionnaire comparing discrepancies in patients/caregivers' assessments and the patients' predictions of their own performances on a memory task.

AD patients with depression (n=21) or without depression (n=21) were asked to complete an assessment of self-reported memory dysfunction (Short Memory Questionnaire; SMQ) and memory task performance prediction (10-words-recall Questionnaire). In addition, the caregivers' evaluations of the memory deficits in the study patients were assessed using the SMQ.

We observed a greater discrepancy in the SMQ scores given by the caregivers' and the patients' among AD patients without depression, compared with those with depression. A greater discrepancy was also observed in the ratio score (patient's predicted performance/actual performance) for the 10-words-recall Questionnaire in AD patients without depression than in those with depression.

AD patients with depression may estimate their memory ability either more accurately or more negatively than AD patients without depression, as shown using the above 2 methods.