Atopic Eczema in Adulthood and Risk of Depression and Anxiety: A Population-Based Cohort Study

Abstract

Background: Atopic eczema is a common and debilitating condition associated with depression and anxiety, but the nature of this association remains unclear.

Objective: To explore the temporal relationship between atopic eczema and new depression/anxiety.

Methods: This matched cohort study used routinely collected data from the UK Clinical Practice Research Datalink, linked to hospital admissions data. We identified adults with atopic eczema (1998-2016) using a validated algorithm, and up to 5 individuals without atopic eczema matched on date of diagnosis, age, sex, and general practice. We estimated the hazard ratio (HR) for new depression/anxiety using stratified Cox regression to account for age, sex, calendar period, Index of Multiple Deprivation, glucocorticoid treatment, obesity, smoking, and harmful alcohol use.

Results: We identified 526,808 adults with atopic eczema who were matched to 2,569,030 without. Atopic eczema was associated with increased incidence of new depression (HR, 1.14; 99% CI, 1.12-1.16) and anxiety (HR, 1.17; 99% CI, 1.14-1.19). We observed a stronger effect of atopic eczema on depression with increasing atopic eczema severity (HR [99% CI] compared with no atopic eczema: mild, 1.10 [1.08-1.13]; moderate, 1.19 [1.15-1.23]; and severe, 1.26 [1.17-1.37]). A dose-response association, however, was less apparent for new anxiety diagnosis (HR [99% CI] compared with no atopic eczema: mild, 1.14 [1.11-1.18]; moderate, 1.21 [1.17-1.26]; and severe, 1.15; [1.05-1.25]).

Conclusions: Adults with atopic eczema are more likely to develop new depression and anxiety. For depression, we observed a dose-response relationship with atopic eczema severity.

Keywords: Anxiety; Atopic dermatitis; Atopic eczema; Depression; Population-based; Severity.

Figure 1

Flow diagram showing the creation of the cohort and reasons for exclusion (1998-2016). ONS, Office for National Statistics; UTS, up-to-standard.

Figure 2

HRs (99% CI) for the association between eczema severity (time-updated) and depression and anxiety. IMD, Index of Multiple Deprivation. All models were fitted to people with complete data for all included variables. Sets without at least 1 exposed and 1 unexposed were excluded. HRs were estimated from a Cox regression model with current age as the underlying time scale, stratified by matched set (sex, age, and general practice). A minimally adjusted model accounted for the matching variables (1,980,710 participants in the depression cohort [1,920,172 unique people] and 2,242,905 in the anxiety cohort [2,171,784 unique people]). The adjusted model additionally included current calendar period (years: 1998-2001, 2002-2006, 2007-1201, and 2012-2016,) and quintiles of IMD at cohort entry (same participants as in the minimally adjusted). A final model, additionally adjusted for potential mediators, also included BMI (categorized as normal, 18.5-24.9 kg/m²; underweight, <18.5 kg/m²; overweight 25.0-29.9 kg/m²; obese ≥30.0 kg/m²), smoking status, and alcohol and high-dose corticosteroid use (≥20 mg/d prednisolone equivalent dose), both as time-updated variables (1,371,005 participants in the depression cohort [1,322,284 unique people] and 1,583,390 in the anxiety cohort [1,583,390 unique people]). *Compared with no atopic eczema. †Depression: P values were less than .0001 for linearity in all models, and for departure from linearity were as follows: minimally adjusted P = .3810; adjusted P = .3832; and additionally adjusted for potential mediators P = .6983. ‡Anxiety: P values were less than .0001 for linearity in all models, and less than .0001 for departure from linearity in all models.

Figure E1

Visual representation of the cohort entry criteria and follow-up process.

Figure E2

Directed acyclic graph illustrating implicitly assumed causal structure underlying our adjusted models.