Increasing Depression Can Predict Higher Dementia Risk

Early stages of dementia may be indicated when symptoms of depression steadily increase in older adults, as indicated in a study linking dementia and depression.  This report was published in The Lancet Psychiatry Journal.

Those diagnosed with dementia commonly show symptoms of depression.  Some might experience depressive symptoms only transiently, followed by full remission while others might have remitting and relapsing depression.  Others might be chronically depressed and this might be linked to different risks of dementia.  The study included 3325 adults aged 55 and over, all showing symptoms of depression but no symptoms of dementia.  Data was gathered from the Rotterdam Study, a population-based study of various diseases in the Netherlands.  The authors tracked depressive symptoms over 11 years and the risk of dementia for a subsequent 10 years.

The authors of the article from the Center for Epidemiology Depression Scale (CES­D) and the Hospital Anxiety and Depression Scale­Depression (HADS­D) identified 5 different trajectories of depressive symptoms­ 2441 participants with low depression symptoms, 369 with initially high symptoms that decreased, 170 with low starting scores that increased then remitted, 255 initially low symptoms that increased and 90 with constantly high symptoms.

Of all these participants, 434 developed dementia, including 348 cases of Alzheimer’s disease. The group with low symptoms of depression had a 10% that developed dementia.  This was used as a benchmark to compare other trajectories of depression.  Of the group whose symptoms of depression increased over time, 22% of these individuals developed dementia.

The Authors state that their findings support the hypothesis that increasing symptoms of depression in older age could potentially represent an early stage of dementia and that dementia and some forms of depression may be symptoms of a common cause.  Molecular levels, the biological mechanisms of depression and neurodegenerative diseases overlap considerably, including the loss of ability to create new neurons, increased cell death and immune system dysregulation.

Dr. Simone Reppermund from the Department of Developmental Disability and Centre for Healthy Brain Ageing at the University of New South Wales, Sydney, Australia, says that several factors can contribute to the development of both depression and dementia.  Depressions, especially steadily increasing depressive symptoms, seem to increase the risk of dementia.  The question of how the presence of depressive symptoms modifies the risk of dementia still remains.  Lifestyle factors such as physical activity and social networks, biological risk factors such as vascular disease, neuroinflammation, high concentrations of stress hormones and neuropathological changes might bring new treatment and prevention strategies a step closer.

It seems that keeping ourselves active and engaged in physical activities might help allay depression for some of the population.  Let’s all work on maintaining a positive attitude and keep busy in our older years with various outside interests.  Beat depression and possibly dementia or Alzheimer’s!

Dr Fredda Branyon