Abstract

We conducted a thorough search across four databases, yielding a total of 565 relevant publications, to determine the relationship between bipolar disorder (BD) and inflammatory bowel disease (IBD). After reviewing 69 full-text publications, removing duplicates using Rayyan quality criteria for research inclusion, and assessing relevance, we ultimately found six papers that met the inclusion criteria. We included six studies with a total of 655,964 IBD patients [383,238 Crohn’s disease (CD) and 270,615 ulcerative colitis (UC)], and 292,407 (44.6%) were males. The prevalence of BD in IBD patients ranged from 0.2% to 9.7%, with a total prevalence of 17,658 (2.7%). Findings indicate an increased prevalence of BD in IBD patients compared to the general population, with variations between CD and UC. Some studies report significantly higher odds of BD in UC patients, while others found no significant difference between CD and UC. The evidence highlights a complex relationship between IBD and BD, with some studies indicating a higher prevalence of BD, especially in cases of comorbidities. To clarify underlying mechanisms and establish causality, further research is necessary. Clinicians should monitor psychiatric comorbidities in IBD patients and adopt a multidisciplinary care approach. Future standardized prospective studies are essential to confirm these associations and develop interventions to enhance physical and mental health outcomes in IBD patients.

Key words: Psychiatric disorders; Bipolar disorder; Inflammatory bowel disease; Ulcerative colitis; Crohn’s disease; Systematic review.