Depression and dementia go hand in hand. There has been a lot of research and discussion about whether or not one causes the other. Some research suggests that elderly depression may increase the risk of dementia, but the underlying cause for that had not been uncovered. New research may have the answer.
It’s a classic “which came first?” puzzle
“Is depression a consequence of the dementia?” asked Robert S. Wilson, Rush University Medical Center in Chicago, IL, study author. “Do both problems develop from the same underlying problems in the brain? Or does the relationship of depression with dementia have nothing to do with dementia-related pathology?”
Eight year study
Wilson and his team analyzed 1,764 people averaged 77 years old who were free of any memory impairment. Each year, for just under eight years, they were assessed for symptoms of depression and took tests which measured their memory capabilities. During the study, 680 people died and autopsies on 582 looked for signs of dementia.
No causal relationship
They found that 315 study participants developed some kind of dementia during the study period. About 922 showed signs of mild cognitive impairment (MCI) which is a precursor to Alzheimer’s disease. There was no relationship found between the levels of brain damage among participants and levels of reported depression. The study concluded that there was no causal relationship between depression and dementia.
Still, depression is key to advancing dementia
They did find that those who developed MCI were more likely to have a higher levelo of depressive symtoms prior to diagnosis, but when compared to those without MCI, they were no more likely to experience any change in symptoms of depression after the MCI diagnosis was made. Similarly, people who developed dementia were more likely to show depressive symptoms prior to diagnosis. Symptoms dropped off rapidly after the dementia diagnosis was made. Depression does seem to cause dementia to progress more rapidly.
Continues to be a risk factor for cognitive decline
While depression does not cause dementia, it is a risk factor. “These findings are exciting because they suggest depression truly is a risk factor for dementia, and if we can target and prevent or treat depression and causes of stress, we may have the potential to help people maintain their thinking and memory abilities into old age,” concluded Wilson.
Source: MedicalNewsToday, Neurology