Do negative thoughts increase risk of Alzheimer's disease?
Researchers from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London have proposed that repetitive negative thinking (RNT), a common symptom of many psychological disorders, may increase the risk of developing Alzheimer's disease.
Until recently, research into Alzheimer's disease has focused on how physical factors are linked to the onset of symptoms. However, scientists at the IoPPN suggest that there are psychological factors that make a person more vulnerable to Alzheimer's disease; and that these factors occur before any physical indicators of the disease emerge.
In an article published in the Journal of Alzheimer's Disease, the researchers argue that a habit of negative thinking over a prolonged period of time (RNT) can have a harmful effect on the brain's capacity to think, reason and form memories. RNT is a common behaviour in people suffering from depression, anxiety, sleep disorders, post-traumatic stress disorder, and life stress; which are themselves associated with increased risk of Alzheimer's. RNT can occur without us being consciously aware of it and consumes our finite capacity of brain resources. Importantly, RNT also triggers a physical stress response in the brain, which over a prolonged period of time may cause damage and reduce the brain's resilience to Alzheimer's disease.
Genetics has been shown to play a role in Alzheimer's disease and people with a particular variant of a gene known as APOE e4 have increased risk of Alzheimer's. However, not everyone who has this gene variant will get Alzheimer's, which suggests that other influences may be involved. Previous research has shown that people who possess this gene variant and who suffer from psychological disorders such as depression are at an even higher risk of developing Alzheimer's.
Robert Howard, Professor of Old Age Psychiatry and Psychopathology at the IoPPN, says: "Treatments that reduce RNT exist, and we believe that they may reduce the risk of Alzheimer's disease. Further research is needed to verify this concept however our new proposal offers a promising line of scientific investigation to reduce the heavy societal burden posed by Alzheimer's disease."
Dr Natalie Marchant, Lecturer in Old Age Psychiatry at the IoPPN, King's College London, says: "We propose that the way that we think may impact our risk for developing Alzheimer's disease. If future research supports this hypothesis this would have implications for the treatment of the disease through psychological interventions."