Plasma Homocysteine Levels and Major Depressive Disorders in Alzheimer Disease

Background: The main aim of this study was to examine the symptomatology of major depression in Alzheimer disease (AD) and its relationship with plasma homocysteine level. Methods: Eighty-three patients with AD were enrolled for clinical assessments and examination of fasting plasma homocysteine. Diagnosis of major depression was made, and the severity of the depression was assessed. Results: The moderate dementia patients presented with more common behavioral disturbances related to major depression than mild dementia patients. Major depression in patients with moderate AD was associated with higher plasma homocysteine levels. Furthermore, a high plasma homocysteine level was positively associated with behavioral disturbance among study participants with major depression. Conclusion: More behavioral disturbance associated with major depression occurred as the dementia progressed. Patients with a higher level of plasma homocysteine presented with a higher behavioral disturbance symptomatology. This finding may account for the relationship between elevated homocysteine levels and depression only in patients with moderate AD. (Am J Geriatr Psychiatry 2010; 18: 1045-1048)