Pathological Ageing Can Be Prevented Through Better Management Of Negative Emotions: Study

The presence of symptoms such as anxiety, rumination and negative emotions could increase the risk of neurodegenerative disease. 

Pathological ageing and neurodegenerative diseases can be prevented through better management of negative emotions, a new study has found. Negative emotions, anxiety and depression promote the onset of neurodegenerative diseases and dementia, but these deleterious effects on the brain can be limited by managing emotions better, and through meditation, for instance. 

The study describing the findings was recently published in the journal Nature Aging. 

Scientists observed brains of young and older adults

As part of the study, neuroscientists at the University of Geneva observed the activation of the brains of young and older adults when confronted with the psychological suffering of others. 

What is emotional inertia?

The researchers observed significant emotional inertia in the neuronal connections of the older adults. This means that negative emotions modify the brains of older adults excessively and over a long period of time, particularly in the posterior cingulate cortex and the amygdala, two brain regions strongly involved in the management of emotions and autobiographical memory. 

What roles do the posterior cingulate cortex and amygdala play?

The posterior cingulate cortex plays an important role in supporting internally-directed cognition, is a highly connected region, and one of the most metabolically active areas of the brain. The amygdala forms the core of a neural system for processing fearful and threatening stimuli, including the detection of threat and activation of fear-related behaviours in response to dangerous stimuli, and is responsible for processing strong emotions such as anger and pleasure. 

What mysteries about the processing of emotions remain unknown?

For two decades, neuroscientists have been looking at how the brain reacts to emotions. In a statement released by University of Geneva, Dr Olga Klimecki, the last author on the paper, said researchers are beginning to understand what happens at the moment of perception of an emotional stimulus. She added that what happens afterwards remains a mystery. 

Researchers are yet to know exactly how the brain switches from one emotion to another, how it returns to its initial state, whether emotional variability changes with age, and what the consequences for the brain of mismanagement of emotions are. 

Which individuals are at higher risk of depression?

An ability to change emotions quickly is beneficial for mental health, previous studies have shown. Meanwhile, individuals who are unable to regulate their emotions and remain in the same emotional state for a long period of time are at higher risks of depression, the statement said. 

What videos were the participants made to watch?

Patrik Vuilleumier, who co-directed the new research, said in the statement that the aim of the researchers was to determine what cerebral trace remains after the viewing of emotional scenes, in order to evaluate the brain's reaction and its recovery mechanisms. The researchers focused on the older adults, in order to identify possible differences between normal and pathological ageing. 

Volunteers were asked to see short television clips showing people in a state of emotional suffering. Some videos were of people trapped in situations such as a natural disaster. There were also videos with neutral emotional content.

What age groups were evaluated?

The researchers observed the brain activity of the participants using functional magnetic resonance imaging (MRI). First, the researchers compared a group of 27 people aged above 65 years with a group of 29 people aged around 25 years, and then repeated the same experiment with 127 older adults. 

How do depression and anxiety affect the default mode network?

Sebastian Baez Lugo, the first author on the paper, said older people generally show a different pattern of brain activity and connectivity from younger people. He added that this difference is particularly noticeable in the level of activation of the default mode network, a brain network that is highly activated in resting state. Depression and anxiety frequently disrupt the activity of the default mode network. This suggests that the default mode network is involved in the regulation of emotions.

What changes are observed in the brains of older adults?

Lugo said that in older adults, the posterior cingulate cortex, which is a part of the default mode network and processes autobiographical memory, shows an increase in its connections with the amygdala, which processes important emotional stimuli. He explained that these connections are stronger in subjects with high anxiety scores, with rumination, or with negative thoughts. Rumination refers to a deep or considered thought about something. 

People with anxiety show stronger emotional inertia

While older people tend to regulate their emotions better than younger people, and focus more easily on positive details, even during a negative event, changes in connectivity between the posterior cingulate cortex and amygdala could indicate a deviation from the normal ageing phenomenon, the study said. These changes in connectivity between the posterior cingulate cortex and amygdala in older adults are accentuated in individuals who show more anxiety, rumination and negative emotions. 

Which region of the brain does dementia affect the most?

One of the regions most affected by dementia is the posterior cingulate cortex. This suggests that the presence of symptoms such as anxiety, rumination and negative emotions could increase the risk of neurodegenerative disease. 

Lugo said researchers still do not know if it is poor emotional regulation and anxiety that increases the risk of dementia or the other way around. He added that the team's hypothesis is that more anxious people would have no or less capacity for emotional distancing, and the mechanism of emotional inertia in the context of ageing would then be explained by the fact that the brains of these people remain 'frozen' in a negative state by relating the suffering of others to their own emotional memories. 

Two types of meditation to prevent dementia

In order to find if it is possible to prevent dementia by acting on the mechanism of emotional inertia, the team is conducting an 18-month interventional study to evaluate the effects of foreign language learning and meditation. 

The authors noted in the paper in order to further refine their results, they will also compare the effects of two types of meditation, namely mindfulness and 'compassionate' meditation. Mindfulness consists of anchoring oneself in the present in order to concentrate on one's own feelings, and 'compassionate' meditation aims to actively increase positive emotions towards others.