IS THERE A ROLE FOR beta-AMYLOID IN DEPRESSION?

Objective: Depression may increase the risk of developing Alzheimer's disease (AD). Recent studies have shown modifications in blood beta-Amyloid (A beta) levels in depressed patients. This literature review examines the potential relationship between A beta-mediated neurotoxicity and pathophysiology of mood disorders. Method: A review of the literature was carried out, through Medline databases, focusing on recent studies reporting alterations of plasma and serum A beta peptides levels in patients suffering from mood disorders. Results: Different data suggest that patients with mood disorders are at great risk of developing cognitive impairment and dementia. In particular, low plasma levels of A beta 42 peptide and a high A beta 40/A beta 42 ratio have been found in depressed patients. In addition, changes in A beta protein levels in patients with mood disorders have been associated with the severity of cognitive impairment and correlated positively with the number of episodes and severity of illness course. Conclusions: Given the intriguing association between change in plasma level of A beta, depression and cognitive impairment, future studies should focus on the relationship between A beta peripheral levels, biomarkers of neurodegeneration and development of dementia in patients affected by mood disorders.