Anxiety and depression linked to seasonal allergies, finds a study

People who suffer from anxiety are more prone to seasonal allergies such as grass allergy and pollen allergy, and those who suffer from depression are more likely to experience frequent perennial allergies triggered by allergens such as animal hair, revealed a study performed by the researchers of Technical University of Munich (TUM).

In the study, the researchers found that allergies such as food allergies and drug allergies were less common in people with generalized anxiety disorder and depression throughout the year.

The researchers interviewed over 1,700 people from the Augsburg area of Germany about their allergies. Led by Claudia Traidl-Hoffmann, Director of the University Center for Health Sciences at University Hospital Augsburg (UNIKA-T) and Professor of Environmental Medicine at TUM, the team differentiated between perennial or non-seasonal allergies - such as those triggered by house dust mites or animal hair, seasonal allergies caused by grass pollen for instance, and allergies to other substances such as food.

The study participants also answered questions about their psychological health. The focus here was on depression, generalized anxiety disorders - which affect all aspects of daily life - and acute mental stress. "There are studies that focus on the psychological components of skin diseases or allergic asthma. For the first time, we are now able to show a connection with seasonal allergies," explains Katharina Harter, the publication's lead author. Around a quarter of those surveyed (27.4%) stated that they suffered from allergies, with 7.7 percent reporting perennial, 6.1 percent seasonal, and 13.6 percent other forms of allergic reactions.

Proven influence of psychological factors

It turned out that people with generalized anxiety disorders also suffered more often from pollen allergies, but not from year-round allergies. Statistically, these were actually less frequent in the group of anxiety sufferers. A possible explanation for this might be that people with persistent allergies develop different coping strategies to deal with stress, which protect them from anxiety disorders.

On the other hand, there was a positive correlation between perennial allergies and depression or depressive episodes. However, the structure of the study did not allow for clarification of whether allergies increase susceptibility to depression or whether depression itself is a risk factor for allergies. What surprised the research team was the fact that psychological factors had little - if any - influence on the occurrence of food and drug allergies.

Possible mitigating factors that could compromise causal relationships were statistically excluded in this study. These included age, smoking/non-smoking status, gender, and family predispositions (e.g. to allergic asthma). However, Harter also outlines the study's weaknesses: "We have a relatively high average age of 61 years, so younger people are rather underrepresented here. The findings are also based on personal reports rather than official allergy diagnoses. But we have blood samples from all participants and intend to scientifically verify this point," she confirms. According to Prof. Traidl-Hoffmann, what this study particularly underscores is the importance of devoting sufficient time to patients. This is the only way to complement clinical evaluations with psychosocial aspects to support an integrated therapeutic approach, such as that practiced by the University Outpatient Clinic for Environmental Medicine at UNIKA-T.