A new study led by University College London has found that “repetitive negative thinking” (RNT) is linked to cognitive decline, as well as deposition in the brain of tau and amyloid, harmful proteins associated with Alzheimer’s.
The research, which has been supported by the Alzheimer’s Association , the research team at University College London, the Institut national de la santé et de la recherche medicale (Inserm) and McGill University, has been carried out with more than 300 people over 55 years of age.
For two years, participants answered questions about how they tend to think about negative experiences, focusing on RNT patterns such as ruminating on the past and worrying about the future . They also completed tests on symptoms of depression and anxiety.
Cognitive function was evaluated, measuring memory, attention, spatial cognition and language. 113 participants also underwent PET brain scans, to measure deposits of tau and amyloid , two proteins that cause the most common type of dementia, Alzheimer’s, when they accumulate in the brain.
Researchers found that people who showed higher RNT patterns – that is, continually had negative thoughts, experienced more cognitive decline over a four-year period, memory decline (one of the earliest signs of Alzheimer’s), and were more prone to amyloid and tau deposits in the brain.
Depression and anxiety were associated with subsequent cognitive decline, but not with amyloid or tau deposits, suggesting that RNT could be the main reason why depression and anxiety increase the risk of Alzheimer’s.
In addition, the researchers point out that these negative thoughts that are repeated all the time could also increase the risk of Alzheimer’s because they act on the indicators of physiological stress , such as high blood pressure. Other studies have found that physiological stress can contribute to amyloid and tau deposition in the brain.
For all this, researchers see positive mental training practices such as meditation, to help create mental schemes that are associated with the positive, regulate negative thoughts and see if this can reduce the risk of suffering from dementia.
“Taking care of mental health is important, and it should be a public health priority, as it is not only important for people’s health and well-being in the short term, but it could also affect their eventual risk of dementia,” he said. Dr. Gael Chételat, study co-author.
Fiona Carragher, research director at the Alzheimer’s Association, sees the study’s findings as very interesting but believes that more research is needed about the connection between repetitive negative thinking, cognitive decline, and accumulation of tau and amyloid in the brain. “Most of the people in the study were already identified as being at higher risk for Alzheimer’s disease, so we would need to see if these results resonate with the general population and if repeated negative thinking increases the risk of Alzheimer’s disease itself. Alzheimer’s, ”Carragher said.
“During these unsettled times, we are hearing daily from people on our Alzheimer’s Association Dementia Hotline feeling scared, confused, or struggling with their mental health. So it’s important to note that this does not mean that a period short of negative thinking causes Alzheimer’s disease. Mental health could be a vital gear in the prevention and treatment of dementia – further research will tell us to what extent, “Carragher said.
Referencia: Repetitive negative thinking is associated with amyloid, tau, and cognitive decline. Natalie L. Marchant, Lise R. Lovland, Rebecca Jones, Alexa Pichet Binette, Julie Gonneaud, Eider M. Arenaza‐Urquijo, Gael Chételat, Sylvia Villeneuve for the PREVENT‐AD Research Group. First published: 07 June 2020. https://doi.org/10.1002/alz.12116
