Title:Different Sides of Depression in the Elderly: An In-depth View on the Role of Aβ Peptides
Volume: 29
Issue: 36
Author(s): Giovanni Pagni*, Claudia Tagliarini, Manuel Glauco Carbone, Bruno Pietro Imbimbo, Donatella Marazziti and Nunzio Pomara
Affiliation:
- Department of Clinical and Experimental Medicine, University of Pisa, via Roma 57, 56100, Italy
Keywords:
Late-onset depression, Aβ-peptides, Alzheimer's disease, amyloid PET, CSF, cardiovascular risk factors.
Abstract:
Background: Late-onset depression (LOD) is the most common neuropsychiatric
disorder associated with Alzheimer's disease (AD), often associated with structural and functional
brain changes, neuropsychological impairments and negative family history for affective
disorders. LOD could be a risk factor or a prodromal phase of AD; this has led to the investigation
of the link between depression and amyloid-β (Aβ) peptides by measuring Aβ levels in
plasma, cerebrospinal fluid (CSF) and brains of elderly depressed subjects.
Objective: This study aims to clarify the complex relationship between depression, Aβ
peptides and AD.
Methods: We evaluated all articles published up to 2019 in PubMed in which Aβ was
measured in serum (or plasma), CSF or brain in elderly with Major Depressive Disorder
or depressive symptoms evaluated with standard scales.
Results: Low plasma Aβ42 levels are strongly associated with depression severity. Plasma
Aβ40 levels are higher in younger depressed, drug-resistant and those with more severe
symptoms. CSF Aβ42 levels are lower in depressed than controls. PET-detected global
and region-specific increases in Aβ deposition are sometimes associated with LOD,
cognitive impairment, anxiety but not with Cardiovascular Diseases (CVDs)/CVD risk
factors. Elderly depressed with CVDs/CVD risk factors have more frequently high plasma
Aβ40 levels and drug-resistance; those without
Conclusion: Two specific Aβ profiles emerge in the depressed elderly. One is associated
with Aβ42 reductions in plasma and CSF, possibly reflecting increased brain amyloid
deposition and prodromal AD. The other one is characterized by high plasma Aβ40 levels,
cerebrovascular disease and is clinically associated with increased AD risk.