Depression, cognitive dysfunction and dementia are among the most debilitating brain diseases in elderly people. They are associated with impaired quality of life, a reduced number of healthy life years, increased care dependency and early death. Many studies show that arterial stiffening could cause brain disorders. The first part of this dissertation shows that aortic stiffening is associated with depression in middle-aged men. Further research shows that carotid artery stiffening in elderly people is not associated with more symptoms of depression after eight years of follow-up. Unlike carotid artery stiffening, aortic stiffening is shown to be associated with cognitive dysfunction after six years of follow-up. The second part of the dissertation studies pathophysiological mechanisms underlying vascular stiffening by analysing whether or not glycated proteins are associated with carotid, femoral and arm arteries. This was shown not to be the case.