Overthinking can cause cognitive decline in older adults, according to new study

We all read frequently about the links between overthinking and physical health – these are usually accepted as a natural progression of ageing.

Researchers have begun to consider dementia as a mental, and not neurological or physical, disease. Amassing evidence now suggests that cognitive decline associated with dementia may start much sooner than previously thought. In fact, cognitive decline can begin at the age of 50.

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Overthinking and physical health – how are they corelated?

It mostly impacts elderly (Image via Unsplash/ Mario Heller)

The study conducted by UCL Psychiatry, involving 292 patients aged 55 and older, found that persistent negative thinking was linked to a decline of cognitive reasoning and revealed indicators of Alzheimer's disease. Dementia affects an estimated 54 million people worldwide, and about a third of dementia cases may be preventable, researchers say.

So, what is this style of thinking that's causing all this trouble? It's called "Repetitive Negative Thinking" and it involves having negative thoughts about the future (worry) or the past (rumination), and these thoughts can feel uncontrollable.

People experiencing mental ill-health frequently engage in this style of overthinking.

Impacts our cognitive health (Image via Unsplash/ robina Weermeijer)

Dr. Natalie Marchant conducted the study, developed a hypothesis called "Cognitive Debt" in 2015. It proposed that repetitive negative thinking could be the "active ingredient" common in all these mental health conditions that may help explain the increased dementia risk we observe.

Their recently published study tested this hypothesis for the first time and found that repetitive negative thinking was indeed associated with indicators of Alzheimer's disease.

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Depression, anxiety, and risk of Alzheimer’s – two sides of the coin

Overthinking leads to depression and anxiety (Image via Unsplash/ Growtika )

The study looked at 292 older adults aged 55+ from the PREVENT-AD project in Canada. Their cognitive function was assessed, measuring memory, attention, spatial cognition, and language. Of these participants, 113 also had their brain scanned, which allowed researchers to measure deposits of tau and amyloid.

These two proteins are biological markers of Alzheimer's disease when they build up in the brain. A further 68 people from the IMAP+ project in France underwent PET brain scans to measure amyloid.

Practising mindfullness (Image via Unsplash/ Brett Jordan)

The findings showed that people who exhibited higher repetitive negative overthinking patterns experienced more cognitive decline over a four-year period. They also had specific declines in memory (which is an early sign of Alzheimer's disease) and had more amyloid and tau deposits in their brain.

While both depression and anxiety were also associated with cognitive decline, they were not associated with deposits of either amyloid or tau.

These findings suggest that repetitive negative thinking could be one reason why depression and anxiety are associated with Alzheimer's disease risk.

It's important to point out that although the hypothesis proposes repetitive negative thinking increases the risk of dementia (specifically Alzheimer's), the opposite might also be true.

It's possible that individuals who experience a decline in their condition may become more concerned or worried about their health which can lead to repetitive negative overthinking.

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Mindfulness and therapy – adopting healthy lifestyle

Regardless of the direction of the effect, the study continues to talk about the importance of maintaining a healthy mind and taking actionable steps to reduce repetitive negative overthinking.

There is a growing body of evidence suggesting that chronic stress is harmful to both your body and brain. Reducing these thinking patterns through cognitive-behavioral therapy or mindfulness may reduce the risk of cognitive decline in older adults.

Although further research is necessary to understand this link, older adults can take positive steps to reduce their risk of dementia. Maintaining healthy lifestyle habits such as a proper diet, regular exercise, and staying socially active are all linked to a lower risk of dementia