Influence of Depression on Working Memory Measured by Digit Backward Span in the Subjects with Mild Cognitive Impairment and Dementia

OBJECTIVES: We aimed to explore the influence of depression on working memory in patients with mild cognitive impairment (MCI) and dementia. METHODS: Clinical and neuropsychological data of 43 subjects with mild cognitive impairment (MCI) (n=17) and dementia (n=26) who had visited Department of Psychiatry at Soonchunhyang University Seoul Hospital, were collected. The subjects were divided into depressed (n=18) and non-depressed (n=25) groups based on the Korean version of Short Geriatric Depression Scale. Two-way analysis of variance test was conducted to evaluate the influence of diagnosis (MCI and dementia), the presence of depression and their interaction on working memory which was measured by digit forward and backward span test. RESULTS: Among the patients with MCI, test score of digit backward span test in depressed group was significantly lower than in non-depressed group. However, among the patients with dementia, there was no significant difference in digit backward span test between depressed and non-depressed groups. CONCLUSION: This study suggests that the depression could deteriorate working memory measured by digit backward span test in patients with MCI, relative to in patients with dementia and it also implicates the diagnostic assessment for depression has clinically importance in patients with MCI.

Association between Characteristics of Brain Magnetic Resonance Imaging and Atypical Antipsychotics Use in Dementia Patients

OBJECTIVES: We aimed to identify the neuroimaging marker for prediction of the use of atypical antipsychotics (AAP) in dementia patients. METHODS: From April 2010 to March 2013, 31 patients who were diagnosed as dementia at the psychiatric department of Soonchunhyang University Hospital, completed the brain magnetic resonance imaging scan and cognitive test for dementia. Ten patients were treated with AAP for the improvement of behavioral and psychological symptoms of dementia (BPSD) and the other 21patients were not. Using T1 weighted and Fluid Attenuated Inversion Recovery (FLAIR) images of brain, areas of white matter (WM), gray matter (GM), cerebrospinal fluid (CSF) and white matter hyperintensities (WMH) have been segmented and measured. Multivariate logistic regression models were applied for assessment of association between AAP use and the GM/WM ratio, the WMH/whole brain (GM + WM + CSF) ratio. RESULTS: There was a significant association between AAP use and the GM/WM ratio (odds ratio, OR = 1.18, 95% confidence interval, CI 1.01-1.38, p = 0.037), while there was no association between AAP use and the WMH/whole brain ratio (OR = 0.82, 95% CI 0.27-2.48, p = 0.73). CONCLUSIONS: The GM/WM ratio could be a biological marker for the prediction of AAP use and BPSD in patients with dementia. It was more likely to increase as dementia progress since atrophy of WM was more prominent than that of GM over aging.