Summary: People with common allergic conditions — including asthma, hay fever and atopic dermatitis — are more likely to report depression, anxiety, bipolar disorder and higher neuroticism scores. Genetic analyses in this study, however, suggest these links are unlikely to be directly causal.
Source: Wiley
In a study published in Clinical and Experimental Allergy, investigators analyzed UK Biobank data and additional genetic evidence to examine the relationship between allergic disease and mental health. While people with allergic conditions showed a higher prevalence of several mental health problems, the genetic analyses did not support a direct causal effect in either direction.
The study found that individuals with asthma, atopic dermatitis (eczema) or hay fever were more likely to report depression, anxiety, bipolar disorder or elevated neuroticism. However, when researchers applied Mendelian randomization — a method that uses genetic variants to probe causality — the associations largely did not hold up as causal relationships.
The authors stress that this does not rule out complex interactions between physical and mental health over time. They recommend further research to determine whether treatments that improve allergic conditions might also influence mental health outcomes, or whether mental health interventions could benefit allergy management.
“Our findings do not exclude the possibility that allergic disease could influence the course of mental health problems, or that mental health could affect allergy progression,” said lead author Ashley Budu-Aggrey, PhD, from the University of Bristol. “Further work investigating these dynamic relationships could identify new strategies for managing both allergic disease and mental health symptoms.”
Senior author Hannah Sallis, MSc, PhD, noted that the study combined evidence from observational analyses and genetic approaches across several datasets. “Using multiple complementary methods strengthens our confidence in the overall pattern of results,” she said. “Understanding whether allergic disease causes mental health problems, or vice versa, is essential to make sure clinical resources and treatments are directed where they will have the most benefit.”
About this mental health research news
Author: Press Office
Source: Wiley
Contact: Press Office – Wiley
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Original Research: Open access.
“Investigating the causal relationship between allergic disease and mental health” by Ashley Budu-Aggrey, Sally Joyce, Neil M. Davies, Lavinia Paternoster, Marcus R. Munafò, Sara J. Brown, Jonathan Evans and Hannah M. Sallis. Clinical and Experimental Allergy
Abstract
Investigating the causal relationship between allergic disease and mental health
Background
Previous observational studies have reported links between allergic disease and various mental health outcomes, but whether those associations reflect direct causal effects has been unclear. This study used Mendelian randomization (MR) alongside observational analyses to investigate if atopic conditions may causally influence mental health traits, or vice versa.
Methods
Researchers first described the observational relationship between a broad allergic disease phenotype and mental health measures using data from the UK Biobank. To test causality, they applied bidirectional two-sample Mendelian randomization using summary statistics from published genome-wide association studies. A genetic instrument capturing variants associated with a broad allergic phenotype was used to probe causal effects on a range of mental health outcomes. The team also examined whether associations differed when focusing specifically on atopic dermatitis, asthma or hay fever. To account for multiple comparisons, a Bonferroni-corrected significance threshold of p < 0.0016 was applied (32 tests).
Results
Observational analyses showed consistent associations between the broad allergic phenotype and higher odds of self-reported depression (ORself-report = 1.45, 95% CI: 1.41–1.50, p = 3.6 × 10−130), anxiety (OR = 1.25, 95% CI: 1.18–1.33, p = 6.5 × 10−13), bipolar disorder (ORself-report = 1.29, 95% CI: 1.12–1.47, p = 2.8 × 10−4) and increased neuroticism (β = 0.38, 95% CI: 0.36–0.41, p = 6.8 × 10−166). Similar observational relationships were observed for asthma, atopic dermatitis and hay fever when analyzed individually, though associations of atopic dermatitis and hay fever with bipolar disorder were weaker. In contrast, Mendelian randomization provided little evidence for a causal relationship in either direction (all MR p-values > .02), indicating the genetic data do not support a straightforward causal link.
Conclusion
The study found strong observational comorbidity between allergic diseases and several mental health traits, but genetic causal inference methods did not replicate most of these associations. Any causal effects detected were much smaller than the observed phenotypic links. These results suggest that much of the clinical co-occurrence of allergy and mental health problems may not be due to direct causal effects, highlighting the need for further research into shared risk factors, environmental influences and the potential for interventions that address both physical and mental health needs.