Hay fever significantly boosts risk of depression and other psychiatric disease, new study finds

Suffering from hay fever or other common allergies significantly increases the risk of depression and anxiety, a major new study suggests.

Analysis of nearly 200,000 people showed for the first time a link between the so-called “three A’s” - allergic rhinitis (hay fever), asthma and atopic dermatitis (eczema) with psychiatric disease.

Previous research has hinted at various causal connections between certain allergies and specific emotional or psychological disorders, but, overall, the picture has been confused.

The new study, however, reveals a widescale association between the two, which experts say should help doctors better predict and prevent mental illness.

They believe inflammation caused by the allergies may also be increasing the likelihood of psychiatric conditions.

The stress of coping with an allergy may also explain the link.

Published in the journal Frontiers in Psychiatry, researchers in used health insurance data to compare 46,647 people with allergies to 139,941 without.

While those without one of the three main allergies had a 6.7 per cent chance of developing a psychiatric disorder within a 15-year period, for those who were allergic the risk was 10.8 per cent.

Unlike previous studies, the team at the Tri-Service General Hospital in Taiwan included patients of all ages.

"As a clinician, I observed that some patients with the three 'A's appeared to suffer emotionally.

We would like to let clinicians who care for patients with allergic diseases know that their risk for psychiatric diseases may be higher," said Dr Nian-Sheng Tzeng, who led the study.

"Assessing their emotional condition and monitoring their mental health could help to avoid later psychiatric problems."

A closer look at the data revealed that people with atopic dermatitis had a lower risk of developing a psychiatric disorder, while those with asthma and allergic rhinitis had a higher risk.

Dr Samantha Walker, Director of Research and Policy at Asthma UK, said: “We are not surprised by the results of this study, but they are concerning.

“We have known for some time that people with long term conditions, like the 5.4 million people with asthma in the UK, are more likely to experience issues with mental health such as depression or anxiety.

“This study is a step in the right direction in showing a link between mental health and asthma, but it’s still not clear whether the relationship is causal, where having one condition directly leads to developing the other, or vice versa.

“More research is needed to understand this, including the reasons why the conditions are linked, and what can be done to best support people with multiple conditions."