P4–162: Differential effect of depression on cognitive and daily function in people with MCI and Alzheimer's dementia

Depression is a common co-morbid disorder in patients with mild cognitive impairment (MCI) or Alzheimer's dementia (AD). This study aimed to investigate the effect of depression severity on cognitive and functional declines in patients with MCI and mild AD. 300 patients with amnestic MCI (aMCI) defined by Clinical Dementia Rating (CDR) score of 0.5, and 53 patients with mild AD defined by CDR score of 1 were included in the study. Depression severities were measured using Geriatric Depression Scale (GDS). Cognitive function tests including mini mental status examination (MMSE), letter fluency, Boston naming test, verbal learning tests, and trail making test-A (TMT-A) were conducted. Blessed Dementia Scale-Activities of Daily Living (BDS-ADL) was utilized to assess daily functioning. In both groups, correlation between GDS with cognitive function measures and BDS-ADL were analyzed. In aMCI group, correlation analysis showed a significant positive correlation between GDS and BDS-ADL (r=0.321, p<0.001), but no significant correlations were observed between GDS and cognitive function measures. In contrast, correlation analysis in mild AD group showed no significant correlation between GDS and BDS-ADL, but a significant positive correlation was found between GDS with TMT-A time (r=0.315, p<0.05). The present study suggests that depression severity has negative impact on daily functioning rather than cognitive functioning in patients with MCI. However, in patients with AD cognitive functioning rather than daily functioning is affected by depression severity.