P652 The burden of mental illness, including deliberate self-harm, before and after a diagnosis of IBD, a UK population study

Abstract

Abstract Background The burden of mental illness among IBD patients is recognised to be greater than among their healthy peers. Due to the bi-directional influence of the gut-brain axis,mental health may be linked to IBD outcomes and vice versa. The aim of this study was to use population level data to describe the incidence of anxiety, depression, insomnia, severe mental illness and deliberate self-harm in patients with IBD. Methods A retrospective cohort study was conducted using The Health improvement Network (THIN) database to estimate the incidence rates of anxiety, depression, insomnia, severe mental illness and deliberate self harm in patients with IBD between 1995 to 2021 and matched controls with no pre-existing mental health illness.The prevalence of pre-existing depression, anxiety and insomnia prior to IBD diagnosis was assessed for IBD patients and matched controls.The association between deliberate self harm and incident mental health diagnoses following IBD diagnosis were estimated using Cox regression analysis. Results We identified 59,613 incident cases of IBD,34,615 (58.1%) had UC and 25,000 (41.9%) had Crohn’s disease. The median age was;41.5 (IQR 29.6–57.5) years,with an equal proportion of males and females with IBD (49.2% vs 50.8%). Patients with a diagnosis of IBD had an increased prevalence of anxiety 10 years (3.0% vs 2.5%,p<0.001) and 2 years prior to diagnosis (6.2% and 5.3%,p<0.001). A similar pattern was seen for insomnia at 10 years (1.0% vs 0.9%, p=0.028) and 2 years (3.4% vs 3.0%, p<0.001) and for depression at 10 years (3.7% vs 4.5%, p<0.001) and 2 years (8.1% vs 9.6%, p<0.001). The incidence of mental illness was higher in IBD patients than controls for; anxiety [6.1 vs 5.3 per 1000 patient years,HR 1.14(1.09–1.20),p<0.001], depression [11.3 vs 7.5 per 1000 patient years,HR 1.34 (1.28–1.39),p<0.001], insomnia [9.6 vs 6.0 per 1000 patient years,HR 1.54(1.5–1.6),p<0.001] and DSH [1.6 vs 1.2 per 1000 patient years,HR 1.20(1.07–1.35),p<0.001]. Associations of deliberate self harm in this patient groups included: IBD (HR 1.20(1.07–1.35),p=0.002),female gender (HR 1.06(1.35–1.60),p<0.001),age quintile <27.4 years (HR 4.48(3.95–5.93),p<0.001) compared to >61.3 years,anxiety (HR 1.57(1.35–1.82),p<0.001),depression (HR 5.97(5.33–6.69),p<0.001),insomnia (HR 2.32(2.02–2.66),p<0.001), and severe mental illness (HR 5.74(4.56–7.22),p<0.001). Conclusion There is an additional burden of mental illness in patients who are later diagnosed with IBD. Following diagnosis,the incidence of depression, anxiety, insomnia and deliberate self harm is higher in individuals with IBD than controls.Patients who develop mental illness in the setting of IBD are at particularly high risk of deliberate self-harm.