PhD defence I.F. (Isabelle) van der Velpen

Below is a brief summary about the dissertation:

Good social relationships in older age are important to maintain good health. “Social health” captures the different elements of social relationships between an individual and their social environment. Previous research has shown that having suboptimal social health increases dementia risk in older age, but it is unknown how or why this happens. The answers to this question may be found in the brain: does social health influence the structure of the brain? The aim of this thesis was to investigate how the biology and structure of the brain is involved in the link between social health and dementia in older adults. 

Chapter 2 showed that the basics of social health include both positive and negative aspects at the same time. Older adults experience social health in a very diverse way. Next, chapter 3 showed that social health is linked to better brain health in older age, and brain regions vital to social health are crucial to dementia risk. Better experienced social support, loneliness and marital status were linked to brain structure in different ways. Finally, chapter 4 showed that the stress system and the immune system are both linked to social health and the brain in unexpected ways. 

In conclusion, social health in older age is very diverse and is linked to changes in the structure of the brain. Marital status and social support were generally protective for brain health, but loneliness was not. Maintaining good social health in diverse aspects of life may help in the prevention of dementia.