International research led by the Centre for Healthy Brain Ageing (CHeBA) at UNSW Sydney suggests that depression is more likely to be attributable to dementia-related brain changes than a risk factor or reaction to the disease.
Depression commonly accompanies Alzheimer’s disease and other dementias, but it has remained unclear whether depression is a risk factor and contributing cause or a result of the brain changes that are associated with dementia.
To address this question, an international study looking at the associations between depression and dementia was conducted using data for 646 older individuals who developed dementia. The data was provided by 8 studies of ageing across 7 countries involved in the Cohort Studies of Memory in an International Consortium (COSMIC), led by CHeBA.
Findings were published in Alzheimer’s & Dementia – The Journal of the Alzheimer’s Association.
Co-author on the research and Leader of the COSMIC Consortium, Professor Perminder Sachdev, said the association between years to dementia diagnosis and successive depressive states was assessed using a mixed effect logistic regression model.
We found that, in general, the chances of having depression increased with increasing proximity to the diagnosis of dementia, said Professor Sachdev, who is also Co-Director of CHeBA.
“This was despite inter-cultural variability in depression rates,” he said.
“Our findings certainly indicate that depression is less likely to be a risk factor or contributing cause of Alzheimer’s disease and other dementias - and more likely a direct result of the brain changes that accompany dementia,” said Professor Sachdev.
Established in 2012, COSMIC is one of four international consortia led by CHeBA to investigate risk and protective factors for dementia incidence and healthy brain ageing world-wide. Support for the consortia’s research is driven by CHeBA’s major philanthropic initiative, The Dementia Momentum.