Recently on ‘The Medic Portal’ I read an article claiming those who suffer depression in adulthood have an increased risk of developing dementia in later years. This particularly caught my eye as I have decided to do my EPQ relating to dementia so I am particularly intrigued by this article.
Scientists at the Erasmus University in Rotterdam tracked 3,325 people over 21 years and discovered that those who had experienced depression for more than three years were over a fifth more likely to go on to have dementia. However, people who suffered episodes of depression and then recovered were not at a greater risk.
The study used individuals with different severities of depression. They found that 21% of people whose depressive symptoms increased over time ended up being diagnosed with dementia. By comparison, only 10% of people with “low symptoms of depression” developed dementia.
But how are the two conditions interlinked? The researchers explained that signs of depression may be an early signal that dementia is developing in the brain before the more recognisable signs such as memory loss are acknowledged. There are a number of potential explanations including that depression and dementia may both be symptoms of a common underlying cause or that increasing depressive symptoms are on the starting end of a dementia continuum in older adults
“The questions are if, and how, the presence of depression modifies the risk for dementia,” Dr Simone Reppermund said. “The study … provides an answer to the first question: Depression, especially steadily increasing depressive symptoms, seems to increase the risk for dementia. However, the question of how the presence of depressive symptoms modifies the risk of dementia still remains.”