Penn State researchers say that chronic lung inflammation associated with childhood asthma is linked to developing anxiety as an adult, according to new research in mice. Published in the journal Frontiers in Behavioral Neuroscience, the study shows that ongoing exposure to allergens in childhood was associated with chronic lung inflammation, which was also linked to genetic changes related to stress and serotonin production. The study also found that asthma attacks contributed to episodes of anxiety.
Research already shows that about 10 percent of children and teens have asthma, and that those young people affected by the condition are two to three times more likely to develop depression and anxiety, according to Penn State News. According to researchers, finding the exact reasons why these conditions are connected is challenging because there are many possible social and environmental triggers for anxiety, such as problems at home or school, allergens, and pollution.
Sonia Cavigelli, associate professor of behavioral health at Penn State, told Penn State News that “The idea of studying this link between asthma and anxiety is a pretty new area, and right now we don’t know what the connection is … What we saw in mice was that attacks of labored breathing may cause short-term anxiety, but that long-term effects may be due to lasting lung inflammation.”
According to a recent press release on the study, researchers studied four groups of mice in order to better understand the connection between lung inflammation and anxiety symptoms. The study’s authors found that even after allergen exposure stopped, the mice still had lung inflammation up to three months later, leading researchers to conclude that lung inflammation might linger long after asthma triggers are resolved. Cavigelli was quoted in the press release as saying that “If this translates to humans, it may suggest that if you grow up exposed to an allergen that you’re reacting to, even if you get over that, you might still have these subtle, long-term changes in lung inflammation.”
Moreover, researchers also found that when mice were exposed to inflammation-causing allergens associated with changes in lung function, they also showed changes in gene expression in areas of the brain linked to stress regulation and serotonin function, according to the press release.
Lead study author Jasmine Caulfield, a graduate student in neuroscience, told Penn State news that “It makes sense to us because while labored breathing events may be scary and cause anxiety in the short term, it’s the inflammation in the airways that persists into adulthood … So it would make sense that long-term anxiety is linked with this long-term physical symptom.”
Researchers also found differences between male and female mice, according to the press release. Caulfield said, “In this study, the female mice had more inflammation in their lungs than the male mice three months after exposure to an allergen … In humans, girls are more likely to have persistent asthma while boys are more likely to outgrow it, so our animal model seems to map onto what we see in humans.”
While more studies are needed to better understand the links between asthma and anxiety, this research is the first to show that chronic lung inflammation is linked to changes in the brain associated with anxiety symptoms, according to the study. Penn State News also notes that the study’s authors plan to continue researching these links, in order to expand upon the current findings.