Stressful situations can cause anxiety, our body’s natural response to stress. But feelings of apprehension can also be accompanied by physical effects like rapid breathing, increased heart rate, and nausea .
How our brain perceives these physical changes, particularly breathing, could be the key to better understanding and treating anxiety disorders.
Anxiety disorders are the most common mental health problem in Europe, affecting some 25 million people across the region.
While anxiety is a normal reaction to difficult times, allowing us to take precautions, people with disorders can have high levels of fear that arise out of nowhere and affect their daily lives .
“You have an anxiety disorder when anxiety levels are high and cause problems,” said Dr. Olivia Faull, a neuroscientist at the University of Zurich in Switzerland. needs to do, like shopping or visiting friends. “
Although existing treatments can help, they are not ideal for everyone. Medications such as serotonin reuptake inhibitors can relieve symptoms, but they can also be accompanied by side effects . Exercise is recommended , as this can activate the front of the brain, helping to control our reactions to real or imagined threats. However, it is not appropriate for people with certain types of anxiety. “It could be too much for someone with severe social anxiety,” said Dr. Faull. “You don’t want to go to class or have a personal trainer.”
Therefore, new treatments for anxiety are needed and could be developed using a new approach. Dr. Faull and other scientists are now investigating the link between anxiety and our ability to perceive what is happening inside our body, called interoception . “It’s a novel field of research and we don’t know much about it yet,” said Dr. Omer Van den Bergh, a health psychology researcher at the University of Leuven in Belgium.
Signs
Interoception consists of perceiving signals from internal organs, such as changes in heart rate or difficulty breathing. When running, for example, most people are aware that their heart beats faster and that it is more difficult to breathe. The feeling of hunger also comes from the sensations of measurement in the intestine.
Research, however, suggests that people with high levels of anxiety may not accurately perceive what is going on inside their body . Early work on this topic found that anxiety disorder sufferers are less sensitive to changes in their breathing compared to healthy individuals. A recent study found that there appear to be differences in the way anxious individuals perceive different bodily signals. Heart signals were measured more accurately compared to respiration.
Dysfunctional interoception is believed to be both a cause and an effect of anxiety. For example, an anxious person may not notice changes in breathing until they become extreme and they suddenly feel dizzy. The physical symptoms then add to your initial worry and make you even more anxious. “If you can’t dissociate symptoms and your thoughts about what makes you anxious, they can feed off of each other,” said Dr. Faull.
Some people with anxiety can also misinterpret their body’s interoceptive signals. Dr. Van den Bergh and his colleagues are particularly interested in how hypochondria and somatic symptom disorders, which involve physical symptoms that cannot be explained medically, affect a person’s perception of their internal state.
Someone may be constantly scared about having a brain tumor, for example. If you become stressed and your breathing and heart rate change, you can misinterpret the physical symptoms. “They can be tested for a brain tumor even if there is very little discrimination on the part of the body,” said Dr. Van den Bergh.
Confusing a benign symptom with a sign of disease has advantages. If you feel out of breath during exercise, for example, your brain has to decide if it’s just a normal side effect or if you’re sick. Assuming you’re sick can be a false alarm, but it ensures that you don’t miss out on a threat that could kill you.
“Prevention is better than cure” is a very important survival mechanism, said Dr. Van den Bergh. “Some people are more prepared than others to apply this strategy depending on how they grew up and the adverse experiences they had in childhood, for example.”
Dr. Van den Bergh and his colleagues hypothesize that anxious people, and particularly those with somatic disorders, are guided by their fears rather than actual symptoms. They developed a paradigm to test their theory that was used in a project called CIP.
“If you are permanently worried about having somatic symptoms, you put your brain in a state of readiness to perceive the things that scare you,” said Dr. Van den Bergh.
A better understanding of how interoception differs in anxious people could lead to new treatments. Dr. Van den Bergh thinks that anxious people could be trained in interoceptive differentiation while adopting an attitude of “letting the information get through” rather than anxiously anticipating a threat. “We think this could be a new route,” he said.
Breathing
The breathing tests themselves could also give a clearer idea of the sensitivity of people suffering from anxiety to respiratory signals. Dr. Faull and her colleagues are investigating how anxiety changes the brain’s perception of interoceptive breath information as part of the ILBAB project. As a first step, they are testing healthy volunteers who experience mild or moderate anxiety to see if there is a difference. In a follow-up project, Dr. Faull wants to address clinical anxiety.
In one experiment, thirty people from each anxiety level group were asked to inhale through a tube and report whether they thought a resistance had been added and, if so, by how much. They were also asked how confident they were in their answer. “It’s like your ability to judge how well you did on a test before you get your grades,” said Dr. Faull.
Preliminary results suggest that people with higher levels of anxiety are slightly less sensitive to changes in breathing, which was expected from previous work using different techniques. Her early findings also suggest that increased anxiety impairs awareness of interoception, or what Dr. Faull refers to as insight.
A different study has shown, however, that anxiety has no effect on perception, but involves a visual task that requires picking up signals from the environment rather than within the body. Dr. Faull thinks this makes sense given that an anxious person might be able to help a friend cope with a crisis, but it may not be logical about a personal problem . “When he turns to himself, and the signals are from himself, then that perception is affected,” he said.
The team’s ultimate goal is to create, based on their findings, specific treatments that include breathing exercises for a number of psychiatric disorders, including clinical anxiety and depression. It might also help patients to better understand the relationship between anxiety and perception of breathing.
Once they have more concrete results, Dr. Faull and her colleagues plan to speak publicly about them as it could help patients better manage their anxiety. Recognizing how anxiety changes perception could be very helpful.
“When someone is in a very great state of anxiety, they need to remember that their perception is probably quite compromised,” Dr. Faull said. “That’s why it can be so overwhelming.”
Rating the effort of breathing
In a series of tests to study anxiety and breathing, the researchers manipulated the participants’ breathing by having them inhale from a resistance-applied breathing system, changing the effort required to breathe. In an experiment with healthy individuals, resistances were presented randomly and the participants rated them based on various factors such as intensity and discomfort. In another task, the same resistances were classified into two groups, A or B, according to their intensity. The four lowest resistances formed category A, while the four highest formed part of category B. Participants were indicated to the category of a stimulus when it was presented and asked to rate it again.
The team found that there were differences in the way stimuli were perceived when presented without and with a category. The participants considered that the stimuli of the same category were more similar than when they were presented without category. The differences between the stimuli of different categories became more pronounced.
The idea behind the tests is that the use of categories, such as low and high intensity, creates expectations and can make a person anticipate a certain type of respiratory stimulus. This readiness effect is similar to the way an anxious person’s fears can influence their interoception. The effect of categorization is expected to be more extreme in anxious people, as they place more importance on their expectations.
However, a study revealed that the relationship is not that simple. The team found that anxious individuals only misinterpreted stimuli that were on the border of two categories and therefore more ambiguous. Therefore, only a stimulus that is not clear can be perceived as a threat. This shows that interoceptive skills in anxious people are flexible and dependent on stimulus, says Dr. Van den Bergh.
ArtÃculo original
This article was originally published in Horizon, the EU Research and Innovation Magazine
