Alzheimer Disease: Scott TM

Qiu WQ, Sun X, Selkoe DJ, Mwamburi DM, Huang T, Bhadela R, Bergethon P, Scott TM, Summergrad P, Wang L, Rosenberg I, Folstein M. · Department of Psychiatry, Tufts-New England Medical Center, Tufts University School of Medicine, Boston, MA, USA. · Int J Geriatr Psychiatry. · Pubmed #17096467 No free full text.

Abstract: BACKGROUND: Depression often precedes the onset of Alzheimer's disease (AD) before the appearance of cognitive symptoms. Plasma Amyloid-beta peptide 42 (Abeta42) declines before and soon after the onset of AD, yet the relationship between plasma Abeta42 and depression is unclear. METHODS: We used 515 homebound elders aged 60 and older in a population-based, cross-sectional study to investigate associations between plasma Abeta levels and depression with and without cardiovascular co-morbidities. Depression was evaluated by using the Center for Epidemiological Studies Depression (CES-D) scale. Plasma Abeta40 and Abeta42 were measured. RESULTS: The elderly with depression had lower plasma Abeta42 (median: 15.3 vs. 18.9, p = 0.008) than those without depression. The CES-D score was inversely associated with plasma Abeta42 (p = 0.001) in subjects with no cardiovascular disease (CVD); however, in the presence of CVD, this association did not exist. Low plasma Abeta42 (OR = 0.41, p = 0.007) and the presence of CVD (OR = 1.84, p = 0.005) were independently associated with depression after adjusting for the confounders of age, stroke and apolipoprotein E4. CONCLUSIONS: Depressive symptoms are associated with low plasma Abeta42 independently of CVD. Prospective studies are needed to determine whether depression associated with low plasma Abeta42 is a separate depression subtype that could predict the onset of AD.

Scott TM, Tucker KL, Bhadelia A, Benjamin B, Patz S, Bhadelia R, Liebson E, Price LL, Griffith J, Rosenberg I, Folstein MF. · Department of Psychiatry, Tufts-New England Medical Center, and Tufts University School of Medicine, Boston, MA 02446, USA. · Am J Geriatr Psychiatry. · Pubmed #15545331 No free full text.

Abstract: OBJECTIVE: There is a growing literature on the relationship between low serum B-vitamins, elevated homocysteine, and cognitive impairment; however, few studies have examined radiological markers of associated neuropathology in geropsychiatry inpatients. The authors examined the relationship of homocysteine, folate, and vitamin B12 with magnetic resonance imaging (MRI) markers of neuropathology. METHODS: In this archival study, authors reviewed the MRIs and medical records of 34 inpatients in a geriatric psychiatry unit. Patients were selected if folate, B12, and/or homocysteine levels had been assessed and if the appropriate clinical MRIs were performed (19 men; mean age, 75 years). Patients with schizophrenia or current substance dependence were excluded. The relationships between MRI volume measures, white-matter hyperintensity (WMH) grade, and serum concentrations of folate, B12, and homocysteine were analyzed, using age-adjusted Pearson correlations. RESULTS: Homocysteine was related to WMH grade, but not brain-volume measures. Folate was associated with hippocampus and amygdala, and negatively associated with WMH. B12 level was not statistically associated with any brain measure. CONCLUSIONS: Elevated homocysteine and low folate were associated with radiological markers of neuropathology. Since no patient had clinically deficient folate, it may be important to rethink what defines functionally significant micronutrient deficiency and explore what this means in different age- and health-status groups. Larger samples will be needed to assess interactions between homocysteine, micronutrients, and other neuropathology risk factors.