Researchers conducted two studies, both of which appear in the American journal Neurology and both of which suggest depression makes dementia more likely, although they do not explain why.
One of the studies followed 1,239 US citizens and looked at the number of times a person experienced depression related to their risk of dementia. It concluded that the more a person experienced depression the higher the risk of dementia and experiencing two periods of depression almost doubled the risk.
Unfortunately the research only highlights the link and reveals nothing about the direct cause. More studies are needed to establish concrete information as to why the two conditions are linked but experts have speculated that brain chemistry and life-style factors such as diet and social time may be contributing factors.
Professor Clive Ballard from the Alzheimer’s Society says more research is needed, “It is well known depression is common in early stages of dementia. What this study demonstrates is that depression at a younger age is probably a significant risk factor for dementia,” he said.