Factors associated with anxiety disorder comorbidity
Molly R. Davies, Kiran Glen, Jessica Mundy, Abigail ter Kuile, Brett N. Adey, Chérie Armour, Elham Assary, Jonathan R. I. Coleman, Kimberley Goldsmith, Colette R. Hirsch, Matthew Hotopf, Christopher Hübel, Ian Jones, Gursharan Kalsi, Georgina Krebs, Andrew M. McIntosh, Geneviève Morneau‐Vaillancourt, Alicia J. Peel, Kirstin L. Purves, Sang Hyuck Lee, Megan Skelton, Daniel J. Smıth, David Veale, James Walters, Katherine S. Young, Johan Zvrskovec, Gerome Breen, Thalia C. Eley
Abstract
BACKGROUND: Anxiety and depressive disorders often co-occur and the order of their emergence may be associated with different clinical outcomes. However, minimal research has been conducted on anxiety-anxiety comorbidity. This study examined factors associated with anxiety comorbidity and anxiety-MDD temporal sequence. METHODS: Online, self-report data were collected from the UK-based GLAD and COPING NBR cohorts (N = 38,775). Logistic regression analyses compared differences in sociodemographic, trauma, and clinical factors between single anxiety, anxiety-anxiety comorbidity, anxiety-MDD (major depressive disorder) comorbidity, and MDD-only. Additionally, anxiety-first and MDD-first anxiety-MDD were compared. Differences in familial risk were assessed in those participants with self-reported family history or genotype data. RESULTS: Anxiety-anxiety and anxiety-MDD had higher rates of self-reported anxiety or depressive disorder diagnoses, younger age of onset, and higher recurrence than single anxiety. Anxiety-MDD displayed greater clinical severity/complexity than MDD only. Anxiety-anxiety had more severe current anxiety symptoms, less severe current depressive symptoms, and reduced likelihood of self-reporting an anxiety/depressive disorder diagnosis than anxiety-MDD. Anxiety-first anxiety-MDD had a younger age of onset, more severe anxiety symptoms, and less likelihood of self-reporting a diagnosis than MDD-first. Minimal differences in familial risk were found. LIMITATIONS: Self-report, retrospective measures may introduce recall bias. The familial risk analyses were likely underpowered. CONCLUSIONS: Anxiety-anxiety comorbidity displayed a similarly severe and complex profile of symptoms as anxiety-MDD but distinct features. For anxiety-MDD, first-onset anxiety had an earlier age of onset and greater severity than MDD-first. Anxiety disorders and comorbidity warrant further investigation and attention in research and practice.