Association between allergic diseases and mental health conditions: An umbrella review

The mental health conditions of allergic diseases have been investigated, but the consistency and magnitude of their effects are unclear. The aim of this umbrella review was to systematically evaluate the published evidence on allergic diseases and mental health conditions to establish a new hierarchy of evidence and identify gaps in this area of research.

We systematically searched PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews from database inception to April 30, 2024. We included systematic reviews that conducted meta-analyses that examined the association of allergic diseases and mental health conditions. We calculated summary effect estimates (odds ratios), 95% confidence intervals, I² statistics, 95% prediction intervals, small study effects, and excess significance biases. We used AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2) to appraise the methodologic quality of the included studies.

We identified 21 eligible articles, which yielded 37 associations (348,405,029 total population) of allergic diseases and mental health conditions. The credibility of evidence was convincing (class I) for asthma and risk of attention-deficit/hyperactivity disorder (odds ratio 1.34, 95% confidence interval 1.24-1.44); and highly suggestive (class II) for allergic rhinitis and risk of tic disorders (2.61, 1.90-3.57), allergic rhinitis and risk of sleep disorders (2.17, 1.87-2.53), food allergy and risk of autism spectrum disorder (2.79, 2.08-3.75), atopic dermatitis and risk of depression (1.60, 1.43-1.79), atopic dermatitis and risk of anxiety (1.62 1.42-1.85), atopic dermatitis and risk of attention-deficit/hyperactivity disorder (1.28, 1.18-1.40), atopic dermatitis and risk of suicidal ideation (1.44, 1.25-1.65), asthma and risk of depression (1.64, 1.50-1.78), asthma and risk of anxiety (1.95, 1.68-2.26), asthma and risk of tic disorders (1.90, 1.57-2.30), asthma and risk of suicidal ideation (1.52, 1.37-1.70), and asthma and risk of suicide attempts (1.60, 1.33-1.92).

Allergic diseases are associated with increased risk of a range of mental health conditions, with the most convincing evidence for asthma. However, these associations do not imply causality, and there is large heterogeneity in these associations, which requires high-quality primary studies to identify causality and strength of evidence.