title: Heterogeneity of elderly depression: increased risk of Alzheimer's disease and Aβ protein metabolism.
abstract: Epidemiological studies have proposed that depression may increase the risk for Alzheimer's disease (AD), even in patients with early-onset depression. Although metabolism of amyloid β protein (Aβ) in elderly depression received attention in terms of their correlation, there is a serious heterogeneity in elderly depression in terms of age at onset of depression. Moreover, it is unknown whether early-onset major depressive disorder (MDD) has a long-term effect on the involvement of Aβ metabolism and later development of AD. Thus, we evaluated serum Aβ40 and Aβ42 levels, the Aβ40/Aβ42 ratio in 89 elderly (≥60 years of age) inpatients with MDD and 81 age-matched healthy controls, and compared them among patients with early-onset (<60 years) and late-onset (≥60years) MDD and controls. The results showed that the serum Aβ40/Aβ42 ratio was significantly higher in patients with both early- and late-onset MDD than in controls (early-onset, p=0.010; late-onset, p=0.043), and it is of great interest that the serum Aβ40/Aβ42 ratio was negatively correlated with the age at MDD onset (R=-0.201, p=0.032). These results suggest that an earlier onset of MDD may have a more serious abnormality in Aβ metabolism, possibly explaining a biological mechanism underlying the link between depression and AD.
authors.affiliation: Juntendo University Mood Disorder Project (JUMP), Department of Psychiatry, Juntendo Koshigaya Hospital, Saitama, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Namekawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Baba
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maeshima
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nakano
authors.forename: Emi
authors.initials: E
authors.lastname: Satomura
authors.forename: Naoko
authors.initials: N
authors.lastname: Takebayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nomoto
authors.forename: Toshihito
authors.initials: T
authors.lastname: Suzuki
authors.forename: Heii
authors.initials: H
authors.lastname: Arai
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000235:genetics*; D016229:Amyloid beta-Peptides / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D053327:Apolipoprotein E4 / Q000097:blood / Q000235:genetics; D002561:Cerebrovascular Disorders / Q000378:metabolism; D003627:Data Interpretation, Statistical; D003863:Depression / Q000150:complications / Q000235:genetics*; D003865:Major Depressive Disorder / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000097:blood / Q000378:metabolism; D012306:Risk; D012959:Socioeconomic Factors
chemical_list: D016229:Amyloid beta-Peptides; D000928:Antidepressive Agents; D053327:Apolipoprotein E4; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)