Depression and anxiety later in life are known risk factors for dementia. Now, new findings published in the journal Alzheimer’s & Dementia suggests that repetitive negative thinking (RNT) may also be a risk factor for Alzheimer’s disease (AD) because of its association with cognitive decline and harmful brain protein deposits linked with the illness, reports University College London News.
For the study, researchers recruited 360 people over age 55. During a two-year period, participants answered questions about their thoughts regarding negative experiences. Scientists focused heavily on RNT patterns, such as rumination about the past and worry about the future, and measured individuals’ symptoms of depression and anxiety.
In addition, researchers assessed the cognitive function of those in the group by measuring their memory, attention, spatial cognition and language. Some people underwent PET brain scans to check for the buildup of two proteins (amyloid and tau deposits) known to cause Alzheimer’s disease—the most common type of dementia—in the brain.
Findings showed that people who registered higher RNT patterns suffered cognitive decline over a four-year period and were more likely to experience declines in memory and amyloid and tau deposits in their brain.
Although depression and anxiety were linked to subsequent cognitive decline, these conditions were not associated with amyloid or tau deposition, which led researchers to believe that RNT might be mainly responsible for how depression and anxiety contribute to Alzheimer’s risk.
“We hope that our findings could be used to develop strategies to lower people’s risk of dementia by helping them to reduce their negative thinking patterns,” said Natalie Marchant, PhD, a senior research fellow at the university and the study’s lead author.
Coauthor Gael Chételat, of the French public research organization Inserm, suggested that since people’s thoughts can positively or negatively affect their physical health, mental training practices such as meditation might help promote positive effects while downplaying negative thoughts.
Chételat encouraged folks to protect their mental health and noted that doctors should consider this a major public health priority because of its significance to overall well-being as well as dementia risk.
Currently, researchers are considering whether mindfulness training or targeted talk therapy could help reduce the risk of dementia-related conditions such as Alzheimer’s.
Click here to learn how the number of Americans with dementia are expected to double by 2040.