A close relationship and two-way communication are present between the brain and the gut, occurring continuously through the brain-gut axis (BGA). BGA is an indirect communication and offers a biological construct to support the biopsychosocial concept of gastrointestinal diseases [17]. Psychiatric disorders often occur in gastrointestinal diseases and vice versa [18].
Many reported works have recently studied the connection between IBD and psychological disorders [19, 20] and have compared the extent of anxiety and depression between subtypes of IBD [21, 22]. Nevertheless, the IBD relationship with psychiatric illness (depression or anxiety) exhibited inconsistency even in a recently reported meta-analysis with eight studies [23]. The results’ heterogeneity was too high without subsequent analysis of the reason.
IBD is a chronic disorder that makes its patients more likely to experience anxiety than the overall population [24]. Depression and anxiety are much more frequent than expected in IBD patients, especially those with CD. UC patients are also more likely to experience anxiety disorders than the general population or patients who are suffering from other chronic disease types [25].
Our study revealed a high depression prevalence (56.2%) and a high anxiety prevalence (37.1%) in our sample. Our findings match those of patients with long-term health problems that generally have an increased risk of major depression [26]. The results were also consistent with other works, indicating that anxiety and depression prevalence in IBD patients exhibited a high level compared to the control group [27].
Byrne et al. noticed that the prevalence of anxiety and depression in patients with IBD (21.2% and 25.8%, respectively) is over that of the general Canadian population. Besides, Thomson and Sulman found more than 25% of people with IBD experienced depression at some point in their lives, while anxiety can affect more than 30% [28].
In patients with IBD, the anxiety rate during remission periods has been estimated to be 29 to 35% and in relapses up to 80% [29]. A Dutch study of 231 patients suffering from IBD found that up to 43% exhibited a higher anxiety level, indicating a psychiatric disorder, and those anxiety symptoms, in addition to psychiatric complaints, are not adequately treated [30].
The rate of differences in depression and anxiety presented in various studies is possible because of variation in the populations under study and the employed methods for depression and anxiety assessment, in addition to the period during which both depression and/or anxiety were evaluated [31].
Regarding the socio-demographic characteristics, we found a significant association between depression and age since depression was more common in older patients, while we did not find differences in terms of sex or marital status.
Like our results, older age was speculated as a risk factor. In a study of Korean origin inactive IBD patients with mood disorders, 40 years of age or older was regarded as an independent indicator of the low life quality [32].
The gender of females as a risk factor in patients with IBD for psychological disorders is controversial. Similar to our results, Nahon et al. found no female predominance in anxious IBD patients [29]. In contrast to our results, females were linked to increased anxiety risk, as reported in various studies of IBD patients and the general population [33]. Female patients are also more prone to depression in several studies [27, 33].
In terms of anxiety and depression prevalence, we found no distinction among UC and CD patients, which agrees with previous studies [34]. On the contrary, Neuendorf et al. found disease type impact with a higher prevalence rate of depressive symptoms in patients with CD than in patients with UC [35].
There was no correlation between both the severity of depression and anxiety and the severity of IBD, either ulcerative colitis or Crohn’s disease. Although we have not found any studies that directly correlate the severity of psychiatric disorders and IBD, we found indirect relationships that reflect the negative effect of IBD severity on anxiety or depression severity. For instance, Nahon et al. and Häuser et al. noticed that IBD activity exhibited a significant association with an increased risk for depression and anxiety in IBD patients [29, 36].
IBD activity is also strongly related to psychological symptoms, as more anxiety symptoms were also seen in flaring periods of patients with IBD [28]. A study in patients with UC stated that endoscopically confirmed active mucosal inflammation was linked to increased psychological stress [37]. Indirectly, patients requiring immunomodulatory and biological therapy for IBD treatment were also at augmented risk of comorbid anxiety and depression associated with the severity of IBD disease [38].
Psychiatric comorbidities can be successfully treated in chronic inflammatory diseases [39], and this may provide improved results in individuals with IBD. Until now, depression and anxiety disorders in people with IBD are not recognized and are not adequately treated. One study estimated that of 43% of people with depression or anxiety symptoms, only 18% received psychological treatment and 21% took psychotropic drugs [30].
Anxiety and depression were considered to have a direct impact on health-related quality of life (HR-QOL) in people with IBD, regardless of disease activity [40]. Zhang et al. investigated depression and disease severity role as individual factors to predict the life quality [41]. Besides, psychiatric disorders of patients with IBD can anticipate costly results, comprising emergency room visits and IBD-related hospitalizations, in addition to high treatment costs [42]. The possible advantages of treatment for mental health, as well as a higher prevalence of depression and anxiety in IBD patients, suggest that screening for depression and anxiety in such a population may be helpful. The brain-gut axis pathophysiology may hold a significant function in IBD, in addition to inflammation and psychological symptoms. TNF-alpha, a pro-inflammatory cytokine, was defined as a key factor. Additional efforts in such areas could showcase future therapeutic targets towards IBD and improve psychological symptoms [43].
As identified herein, the high prevalence of mental disorders represents a major issue, requiring particular concern. Since psychiatric disorders have a significant impact on disease progression, relapse rates, treatment outcomes, and life quality, it is important to foster collaboration between gastroenterologists and psychiatrists. Detection of psychiatric disorders in patients with CD and UC should be part of the medical approach to IBD. Achievement of psychological remission and remission of somatic symptoms appears to be a promising result in IBD treatment [44].