New York, Sep 25 (IANS): Children suffering from asthma are more likely to develop the risk of anxiety during adulthood, finds a new study.

In the study on mice, a team from the Pennyslvannia State University and Cornell University, found that childhood exposure to allergens was linked to persistent lung inflammation and was also connected to changes in gene expression related to stress and serotonin function.

The team also found that episodes of laboured breathing were associated with short-term anxiety.

"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," said Sonia Cavigelli, associate professor at the varsity.

"What we saw in the mice was that attacks of laboured breathing may cause short-term anxiety, but that long-term effects may be due to lasting lung inflammation," Cavigelli added.

According to the researchers, finding the root cause of this connection is difficult because apart from the biological aspects of asthma, there are many social and environmental factors that could lead to anxiety in humans. This includes air pollution or a parent's anxiety.

In the study, the team categorised four groups of mice: one with airway inflammation due to dust mite exposure; one that experienced episodes of laboured breathing and both conditions and that experienced neither, as a control.

The study, published in the journal Frontiers in Behavioural Neuroscience, on 98 mice, revealed that three months after being exposed to the allergen, mice still had lung inflammation and mucus.

This suggests that even when allergy triggers are removed, there are lasting effects in the lungs long into adulthood.

These mice also showed changes in gene expression in brain areas that help regulate stress and serotonin.

There were also differences in the results between male and female mice, the researchers observed.