Inflammatory bowel diseases, including Crohn's disease and ulcerative colitis, are chronic disorders that cause inflammation of the gastrointestinal tract,1 and for which incidence and prevalence are increasing worldwide.2 These diseases are thought to arise from dysregulation of the innate and adaptive immune systems,3 leading to an abnormal inflammatory response to commensal bacteria in a genetically susceptible individual.4 Although a better understanding of the disease together with newly developed drugs have improved prognosis and life expectancy in patients with inflammatory bowel disease (IBD),5, 6 an increased life span with a chronic disease is likely to negatively affect the patient's quality of life.7 For instance, patients with IBD report loss of work productivity, and their disease seems to influence career choice and the decision to retire early.8
In addition, because IBD is a lifelong condition with chronic symptoms, reduced quality of life and social functioning, and no cure, with bidirectional communication via the gut–brain axis,9 patients with IBD might have psychological illness,10 including symptoms of common mental disorders and somatisation.11, 12 Psychological illness further negatively affects quality of life and disease outcomes.13, 14, 15, 16, 17 An analysis of data on administrative claims showed that both direct and indirect costs of care were significantly higher for patients with IBD and a co-existent common mental disorder than for patients with IBD only.18
Research in context
Evidence before this study
As inflammatory bowel disease (IBD) is a lifelong condition with chronic symptoms, reduced quality of life and social functioning, and no cure, patients with IBD might experience symptoms of common mental disorders, including those of anxiety and depression. Uncertainties remain about the magnitude and strength of the association between symptoms of anxiety and depression and the different types of IBD, the influence of disease activity, and sex. A comprehensive search of the medical literature using MEDLINE, Embase, Embase Classic, and PsycINFO identified two systematic reviews that have examined some of these issues, but the literature search used in these reviews only included studies published up to 2014.
Added value of this study
We did a contemporaneous systematic review and meta-analysis to assess prevalence of symptoms of anxiety or depression in adult patients with IBD. We investigated whether type of IBD, disease activity, or sex influence the prevalence, as well as whether prevalence varied on the basis of questionnaire and cutoff used. Pooled prevalence of anxiety symptoms in patients with IBD was 32·1%, and pooled prevalence of depression symptoms was 25·2%, but this pooled prevalence varied according to the questionnaire used. Women with IBD had a higher probability of experiencing anxiety symptoms than did men with IBD, particularly women with Crohn's disease. Patients with active disease also had a higher probability of experiencing both anxiety symptoms and depression symptoms than did patients with inactive disease.
Implications of all the available evidence
These data provide a useful primer for clinicians, as to which patients should be screened routinely for symptoms of common mental disorders, and suggest that there is a need to assess for symptoms of anxiety and depression using validated disease-specific screening tools. Encouraging gastroenterologists to screen for and treat these disorders might improve outcomes for patients.
Although numerous studies have reported symptoms of anxiety and depression in patients with IBD, they show that prevalence rates vary greatly, by up to 80% in some studies.19, 20 Some of this variation might reflect differences in the psychometric tools used to define the presence or absence of these disorders,19, 21, 22 but uncertainties remain about the magnitude of this problem,23 as well as about the strength of association between symptoms of common mental disorders and type of IBD,13, 24, 25 disease activity,26, 27, 28 and sex.29 Two systematic reviews have examined some of these issues,30, 31 but the literature search used only included studies published up to 2014. Although one of these systematic reviews examined these issues in detail,30 a meta-analysis was not done and pooled prevalence estimates were not calculated; the other systematic review did only a few analyses.31
We did a contemporaneous systematic review and meta-analysis to assess the prevalence of symptoms of anxiety or depression in adult patients with IBD. We aimed to investigate whether type of IBD, disease activity, or sex influenced the prevalence of these symptoms, as well as whether prevalence varied on the basis of questionnaire and cutoff used. Synthesising the existing evidence to provide an estimate of the prevalence of symptoms of anxiety and depression will hopefully increase awareness among clinicians, facilitating screening of patients for evidence of these disorders and, if necessary, referral for treatment. Such treatment might also serve to reduce the total burden of disease in these patients, given that there is increasing evidence that mood influences IBD activity.13, 14, 15, 16, 17