Research on the correlation between inflammatory bowel disease and depression: A bibliometric analysis

Abstract

Background:

The aim of this study was to conduct a bibliometric analysis of published studies on the relationship between inflammatory bowel disease (IBD) and depression. The study also aims to identify the major researchers, institutions, and countries and regions in this field to identify current research hotspots.

Methods:

The Web of Science Core Database in the Science Citation Index Expanded database was selected as the data source and was searched to obtain relevant literature on IBD and depression. Bibliometric analysis of relevant publications was performed by utilizing VOSviewer, CiteSpace, bibliometrix, and Microsoft Excel 2019.

Results:

A total of 393 papers were included from January 1, 2014, to December 25, 2023, showing a general upward trend in the number of publications. There were 48 countries and 743 institutions, of which the United States had the largest number of publications. There were 2250 authors involved in research in the field, with clear collaborations between authors. There were currently 163 journals that have published research on this topic, with IBDs being the most cited journal. IBD and depression-related studies are gradually gaining attention from researchers, and the research direction is gradually expanding to epidemiology, gut microbiota, and other related topics.

Conclusion:

This study comprehensively summarizes the research trends and developments of IBD and depression through bibliometrics. This information points out the research frontiers and hot directions in recent years, which will serve as a reference for researchers in this field.

1. Introduction

In recent times, public health has been severely impacted by 2 major diseases known for their long-lasting nature and high rates of illness: inflammatory bowel disease (IBD) and depression. Characterized by persistent inflammation and a tendency for recurrence, IBD is a gastrointestinal tract inflammatory condition, primarily consists of ulcerative colitis (UC) and Crohn disease (CD).^[1] Depression, a widespread mental disorder, typically presents with symptoms like mood depression, sleeping disturbances, and reduced appetite, and can lead to suicidal tendencies in extreme cases.^[2] Studies have demonstrated that these 2 conditions negatively impact each another,^[3,4] increasing the disease and pain burden for patients. Prolonged medication, necessitated by the extended course of IBD, has been linked to the onset of depression. Research indicates that individuals with IBD have a higher likelihood of being diagnosed with depression than those without, while people with a history of depression show an increased propensity to develop IBD.^[5] A meta-analysis revealed that the incidence of depression is greater in individuals suffering from IBD, noting a 38.9% prevalence rate among those with active IBD.^[6] Lately, the correlation between IBD and depression has emerged as a focal point in multidisciplinary research, yet there is a scarcity of published bibliometric analyses on this topic.

The field of bibliometrics, initiated by Alan Pritchard in the 1970s,^[7] has seen a surge in relevance and use across diverse fields, particularly due to the exponential growth of the internet. The analysis of bibliometrics employs statistical and mathematical techniques to discern trends and depict the developmental trajectory of a specific study area. An analysis of bibliometric data concerning IBD and depression was conducted to offer fresh insights into the prevailing research themes and trends associated with these illnesses. This research is instrumental in directing future foundational and clinical inquiries into the comorbidities of IBD and depression.

Visualizing research in the areas of IBD and depression is essential, surpassing the scope of conventional review articles, as it enables the representation of contemporary publications and facilitates the forecasting of emerging frontiers. A superior visualization study can significantly economize the time of researchers seeking new frontiers and hotspots in related domains. Consequently, we have gathered pertinent articles from the last decade using the Web of Science Core Collection (WoSCC) database and employed tools like CiteSpace, VOSviewer, and the “bibliometrix” R package for bibliometric and visual analyses. This approach aims to reveal current global developments and delve into the hotspots and avant-garde trends, offering substantial assistance to researchers.

2. Materials and methods

2.1. Data sources and search strategy

The Web of Science stands as an internationally acknowledged database for scientific citations, renowned for its multidisciplinary scope, high quality, and significant impact, and is extensively utilized in the field of bibliometric analysis.^[8,9] Consequently, this study sourced all its articles from the Science Citation Index Expanded within the WoSCC, to affirm the authoritative and impactful nature of the publications used. This research undertook a comprehensive article search focusing on IBD and depression, covering the period from January 1, 2014, to December 25, 2023. The search for articles was completed within a single day to minimize the likelihood of errors. An advanced search strategy was utilized, employing the formula: TS = (“Inflammatory bowel disease” OR “ulcerative colitis” OR “Crohn disease”) AND TS= (“Depression” OR “depressed” OR “despondent” OR “gloomy” OR “depressive”). In the end, a total of 2185 articles were chosen for inclusion. Selection criteria included: (1) type of publication: review articles and research articles; (2) language restriction: English. The titles, abstracts, and full texts of the articles were meticulously examined by 2 reviewers to verify their relevance to the subject matter. Subsequently, 393 articles specifically addressing IBD and depression were incorporated into the study. The workflow of the search process for this study is depicted in Figure 1. For the articles fulfilling these criteria, comprehensive records (comprising author, title, publication details, abstract, keywords, references, etc) were exported, saved as plain text, and compiled as download_txt files, compatible with CiteSpace for analysis.

Figure 1.

Flow chart of document selection and identification.

2.2. Data analysis

A thorough analytical methodology was employed in this study to examine the trends in IBD and depression research. The analysis of the data was conducted using tools such as VOSviewer (version 1.6.17), CiteSpace, R-bibliometrix (6.1.R2), and Microsoft Office Excel. The publications were analyzed with a focus on authors, journals, references, countries, institutions, and keywords. The 3 analytical tools offer distinct advantages in the realm of bibliometric analysis.

VOSviewer, a bibliometric visualization and analysis tool, was developed by Leiden University in the Netherlands and operates on the Java platform.^[10] VOSviewer’s capabilities enable the creation of visualization and discovery maps, analyzing aspects like countries and regions, research institutions, journals, authors, and references. VOSviewer software parameter settings: normalization method: association strength; the minimum publication thresholds for countries/regions, institutions, and authors are 3, 3, and 5, respectively; the minimum citation thresholds for journals, authors, and references are 30, 30, and 20. VOSviewer excels in drawing nodes and connecting lines between them, offering a clearer depiction of relationships compared to CiteSpace. Therefore, VOSviewer was utilized to analyze the interconnections among countries and regions, research institutions, journals, authors, and references within the publications.

CiteSpace V6.2.R6,^[11] developed by Chaomei Chen, is a Java-based application designed for data visualization, known for its superior ability to effectively respond to the measured data from literature. CiteSpace software parameter settings: time span: January 2014 to December 2023; years per slice: 1; node types: keyword, journal, reference. The remaining settings maintain the software default. Consequently, a clustering analysis of keywords is conducted, and a dual-map overlay of journals is created using CiteSpace.

Bibliometrix^[12] (https://www.bibliometrix.org), a scientometric and bibliometric tool that provides information on producing word clouds of keywords and collaborative world map.

Microsoft Office Excel (v2019; Microsoft Corporation, Redmond) is utilized for the quantitative analysis and generation of visual representations of the annual total number of publications.

3. Results

3.1. Global publishing trend

A total of 393 articles focusing on depression and IBD were collected for the period from January 1, 2014, to December 25, 2023. Annual publication counts serve as a significant marker for identifying trends in research on these topics. There has been an ascending trend in the number of articles over the past decade, signifying growing research interest in IBD and depression. The annual count of publications can indicate the academic interest in a topic, hence the yearly publication numbers and their growth rates are depicted in a histogram (Fig. 2). A consistent increase in publication numbers over the last decade illustrates the growing emphasis researchers are placing on this topic. Between 2014 and 2021, the annual publication figures increased from 19 to 68, with the peak occurring in 2021. In 2022, there was a slight decrease in publications, followed by a 10% rise in 2023 compared to the preceding year.

Figure 2.

Annual growth trend of publications associated with IBD and depression. IBD = inflammatory bowel disease.

3.2. Distribution and contribution of countries/regions and institutions

To evaluate potential collaborations and contributions among various countries and regions, a co-occurrence map of countries and institutions was generated using VOSviewer, as shown in Figure 3C. Cooperation between 2 countries or regions is represented by a red line in the map, with its thickness indicating the extent of their collaboration. Studies on IBD and depression have been conducted by a total of 48 countries. Furthermore, Table 1 displays the top 10 countries with the highest number of publications and their total link strength. The United States leads with the highest publication count (114 [29%]), followed by China (79 [20.1%]), and the United Kingdom (41 [10.43%]). The findings indicate that the majority of articles in this field originate from North America, Australia, and Asia. As per the inter-country collaboration network (Fig. 3A), the UK demonstrates the most intense collaboration (29), suggesting more extensive cooperation with other countries, with the US (24) and Australia (20) following.

Figure 3.

IBD and depression-related research by country or region and their institutional distribution. (A) Distribution of countries with IBD and depression and international collaboration. (B) Institutional distribution of IBD and depression. (C) Map of national/regional collaborations. IBD = inflammatory bowel disease.

Table 1.

Top 10 countries/regions in terms of number of publications.

Rank	Country	Documents	Citations	Total link strength
1	United states	114	3215	24
2	Peoples r China	79	970	12
3	United Kingdom	41	2115	29
4	Canada	36	1615	15
5	Australia	26	1232	20
6	Italy	19	458	8
7	Switzerland	14	828	4
8	South Korea	12	155	0
9	Spain	12	467	6
10	Netherlands	11	329	6

An analysis was also conducted on the primary institutions engaged in this research area. In order to analyze the collaborative relationships and contributions between organizations, this study used the organization network diagram generated by VOSviewer (Fig. 3B). Table 2 enumerates the top 10 most prolific institutions in this field. Leading the list, the University of Manitoba in Canada has published the greatest number of articles (21 articles). The University of Pittsburgh in the United States ranked second with 16 articles, followed by the University of Calgary in Canada with 15 articles, and the University of North Carolina in the United States also contributing 16 articles. All of the top 10 most active institutions in this study are based in Western countries.

Table 2.

The top 10 activist institutions.

Rank	Institutions	Countries/regions	Article counts	Total citations	Average citations per article
1	University of Manitoba	Canada	21	1116	53.14
2	University of Pittsburgh	United States	16	487	30.44
3	University of Calgary	Canada	15	670	44.67
4	University of North Carolina	United States	13	374	28.77
5	Dalhousie University	Canada	12	517	43.08
6	St James’s University Hospital	United Kingdom	10	703	70.30
7	King’s College London	United Kingdom	9	183	20.33
8	The University of Adelaide	Australia	9	723	80.33
9	The University of Melbourne	Australia	8	546	68.25
10	University Hospital Zurich	Switzerland	8	489	61.13

3.3. Distribution of journals

A dual-map overlay is organized by journal topics, illustrating various citation paths in different colors, which symbolize the interconnections among citations. This study identified 4 primary pathways in Figure 4C. Most articles in this study were published in journals related to neurology, immunology, medicine, and clinical practice, and they predominantly cited journals in psychology, health, nursing, and medicine.

Figure 4.

The visualization of journals. (A) Co-occurrence clustering map for journals. (B) Timeline visualization of co-citation among journals. (C) The dual-map overlay of journals.

A significant number of journals have published research articles on IBD and depression. Table 3 shows the 10 journals with the highest number of publications and the 10 most cited journals in this field. Figure 4A shows the knowledge map of journal co-citation network and Figure 4B shows a timeline visualization of journal co-citation. The Inflammatory Bowel Diseases is at the forefront of the top 10 academic journals in the area of IBD and depression, leading both in the number of published articles and frequency of citations. The analysis of co-citations among academic journals revealed that Inflammatory Bowel Diseases led with 1927 co-citations, followed by Gastroenterology with 823 and American Journal of Gastroenterology with 784. Gastroenterology, among the 10 most frequently cited journals, boasted the highest Impact Factor (IF) of 29.4. Seventy percent of the most co-cited journals among the top 10 were classified as Q1, as shown in Table 3.

Table 3.

Top 10 journals with the most publications and top 10 co-citations for papers on IBD and depression.

Rank	Journal title	Article counts	IF	Quartile in category	Rank	Co-cited-journal	Citations	IF	Quartile in category
1	Inflammatory bowel diseases	50	4.9	Q1	1	Inflammatory bowel diseases	1927	4.9	Q1
2	Journal of Crohns & Colitis	14	8.0	Q1	2	Gastroenterology	823	29.4	Q1
3	Alimentary pharmacology & therapeutics	13	7.6	Q1	3	American Journal of Gastroenterology	784	9.8	Q1
4	Journal of pediatric gastroenterology and nutrition	13	2.9	Q2	4	Journal of Crohns & Colitis	630	8.0	Q1
5	Journal of psychosomatic research	12	4.7	Q2	5	GUT	509	24.5	Q1
6	Journal of clinical medicine	9	3.9	Q2	6	Alimentary pharmacology & therapeutics	482	7.6	Q1
7	Frontiers in psychiatry	8	4.7	Q2	7	Clinical Gastroenterology and Hepatology	447	12.6	Q1
8	Scientific reports	8	4.6	Q2	8	Journal of Psychosomatic Research	349	4.7	Q2
9	Clinical Gastroenterology and Hepatology	7	12.6	Q1	9	Digestive Diseases and Sciences	237	3.1	Q3
10	Digestive diseases and sciences	6	3.1	Q3	10	World Journal of Gastroenterology	229	4.3	Q2

IBD = inflammatory bowel disease.

3.4. Authors and authors’ co-citations

From January 1, 2014, to December 25, 2023, a total of 2250 researchers have published papers on the topic of IBD and depression. Charles N. Bernstein, from the University of Manitoba, is the most published and influential author in this field. Table 4 lists the top 10 authors and co-cited authors in the field. Figure 5A shows Author network map and Figure 5B shows co-cited author network map. Co-citing authors: defined as those whose names appear together in 2 or more subsequent articles, demonstrate a co-citation relationship.

Table 4.

Top 10 authors and co-citing authors for IBD and depression.

Rank	Authors	Count	Co-cited authors	Citations
1	Bernstein CN	19	Mikocka-Walus A	392
2	Graff LA	12	Gracie DJ	155
3	Marrie RA	12	Graff LA	152
4	Patten SB	12	Ananthakrishnan AN	135
5	Fisk JD	11	Bernstein CN	128
6	Bolton JM	10	Marrie RA	107
7	Ford AC	10	Szigethy E	98
8	Lix LM	10	Knowles SR	85
9	Rogler G	10	Neuendorf R	82
10	Walker JR	10	Fuller-Thomson E	81

IBD = inflammatory bowel disease.

Figure 5.

Author network and co-cited author network maps. (A) Visual analysis of authors (B) Co-cited authors.

3.5. Distribution of co-cited references

Over the last 10 years, research on IBD and depression has generated 13,290 co-cited references. Table 5 shows the top 10 co-cited references, reveals that each reference was mentioned in co-citations at least 20 times, with 2 references reaching a peak citation count of 82. For constructing the co-citation network map, we focused on references that were co-cited 35 times or more. As depicted in Figure 6, there is a notable co-citation relationship between “Mikocka-Walu, 2016, Clin Gastroenterol Hepatol,” and “Neuendorf R, 2016, J Psychosom Res” with other works such as “Graff LA, 2009, Inflamm Bowel Dis,” “Mikocka-Walu, 2016, Inflamm Bowel Dis,” and “Walker JR, 2008, Am J,” among others.

Table 5.

Top 10 co-cited references on research of IBD and depression.

Rank	Article title	First authors	Journal	Publication year	Citations
1	Symptoms of depression and anxiety are independently associated with clinical recurrence of inflammatory bowel disease[13]	Mikocka-Walus A	Clinical Gastroenterology and Hepatology	2016	82
2	Depression and anxiety in patients with inflammatory bowel disease: A systematic review[14]	Neuendorf R	Journal of Psychosomatic Research	2016	82
3	Depression and anxiety in inflammatory bowel disease: A review of comorbidity and management[15]	Graff LA	Inflammatory Bowel Diseases	2009	81
4	Controversies revisited: A systematic review of the comorbidity of depression and anxiety with inflammatory bowel diseases[16]	Mikocka-Walus A	Inflammatory Bowel Diseases	2016	81
5	The Manitoba IBD cohort study: A population-based study of the prevalence of lifetime and 12-month anxiety and mood disorders[17]	Walker JR	American Journal of Gastroenterology	2008	79
6	The hospital anxiety and depression scale[18]	Zigmond AS	Acta Psychiatrica Scandinavica	1983	76
7	Impact of depressive mood on relapse in patients with inflammatory bowel disease: A prospective 18-month follow-up study[19]	Mittermaier C	Psychosomatic Medicine	2004	69
8	Depression and inflammatory bowel disease: Findings from 2 nationally representative Canadian surveys[20]	Fuller-Thomson E	Inflammatory Bowel Diseases	2006	61
9	A simple index of Crohn-disease activity[21]	Harvey RF	Lancet	1980	57
10	Bi-directionality of brain–gut interactions in patients with inflammatory bowel disease[22]	Gracie DJ	Gastroenterology	2018	56

IBD = inflammatory bowel disease.

Figure 6.

The visualization of co-cited reference in research of IBD and depression. IBD = inflammatory bowel disease.

3.6. Reference with citation bursts

In our research, identified by CiteSpace, there are 15 notable references exhibiting significant citation bursts. This term refers to a notable and rapid increase in how frequently a document is cited within a brief timeframe. Figure 7 illustrates that the reference with the most pronounced citation burst (having a burst strength of 11.23) is “Depression and anxiety in patients with inflammatory bowel disease: A systematic review” by Neuendorf, R et al, experiencing peak citations from 2016 to 2018. Following closely is the study “Symptoms of depression and anxiety are independently associated with clinical recurrence of inflammatory bowel disease,” authored by Mikocka-Walus, A et al in Clinical Gastroenterology and Hepatology, showcasing a citation burst strength of 10.87 and prominent citations from 2018 to 2021. The burst strength of these 15 references varied between 4.31 and 11.23, with their endurance lasting between 2 and 5 years.

Figure 7.

The emergent map of references. The red horizontal stripes represent the years with the most frequent keywords. The blue horizontal stripes represent the years with the most infrequent keywords.

3.7. Distribution of keywords

Keyword indexing plays a key role in quickly deciphering the core themes of a paper, making keyword co-occurrence analysis an effective tool for identifying trends and innovative themes in a given field. Table 6 presents the 20 most frequently occurring keywords in research on IBD and depression. In Figure 8A, which is generated for keywords occurring together more than 4 times, with darker shading occurring the more frequently the keywords appeared. The most common co-occurring keywords are “inflammatory bowel disease,” “depression,” “anxiety,” “Crohn disease,” “ulcerative colitis,” and “quality of life.” Figure 8B illustrates the keyword overlay visualization. Here, we utilized VOSviewer software to differentiate keywords by color based on their average year of appearance, with the most recent ones in yellow and the oldest in blue, indicating a timeline-based division. Figure 8C depicts the keyword visualization network, which can be divided into 5 distinct clusters, each representing a different research direction. To concisely showcase the most emphasized keywords in research on IBD and depression, a word cloud was created from the extracted keywords. This word cloud is displayed in Figure 8D, where the size of each keyword visually represents its frequency of occurrence. Keyword citation burst detection can show the academic hotspots and academic research trends in a certain field. Among the top 12 keywords with the highest citation explosion, “cognitive behavioral therapy” attracted the most attention from researchers over the past 10 years, as shown in Figure 9. In addition, “brain” and “major depressive disorder” received greater attention from 2019 to 2023, while “inflammatory bowel disease” became a research hotspot in 2023.

Table 6.

Top 20 keywords on research of IBD and depression.

Rank	Keywords	Counts	Rank	Keywords	Counts
1	Inflammatory bowel disease	207	11	Colitis	11
2	Depression	163	12	Stress	10
3	Anxiety	82	13	Antidepressants	9
4	Crohn disease	69	14	Disease activity	9
5	Ulcerative colitis	69	15	Health-related quality of life	9
6	Quality of life	34	16	Inflammation	9
7	Fatigue	20	17	Pediatric inflammatory bowel disease	9
8	Mental health	17	18	Psychotherapy	9
9	Gut–brain axis	13	19	Psychology	8
10	Irritable bowel syndrome	13	20	Abdominal pain	8

IBD = inflammatory bowel disease.

Figure 8.

The distribution of keywords. (A) The density visualization map of keywords. (B) Timeline visualization of co-occurrence among keywords. (C) Co-occurrence clustering map for keywords. (D) Word cloud of the most common keywords in IBD and depression research. IBD = inflammatory bowel disease.

Figure 9.

Top 12 keywords with the strongest citation bursts.

4. Discussion

IBD is a chronic condition marked by both intestinal and systemic inflammation, playing a crucial role in the development and progression of depression, as inflammation is a key factor in this context.^[23,24] The prevalence of depression in patients with IBD is twice as high as in the general population, and the comorbidity of depression in patients with active IBD is about 34%.^[16] There is a significant interrelation between IBD and depression, influencing each other.^[25] Over the past decade, the research on the intersection of these 2 fields has garnered increasing attention. This study analyzes trends and focal points in IBD and depression research from 2014 to 2024, utilizing bibliometric techniques. Our findings indicate a growing trajectory in the volume of literature on this subject, particularly noticeable in 2021, which witnessed the highest publication count within the decade. The year 2021 experienced a remarkable surge in publications: 1.87 times more than in 2020 and 3.57 times that of 2014. Although there was a marginal dip in the publication count in 2023 compared to the peak in 2021, the overall volume of research output remained significantly high.

The study’s geographical and institutional analysis highlights that the United States, China, and the United Kingdom are leading in terms of the volume of published literature in the area of IBD and depression research. Notably, the United States and the United Kingdom are more actively engaged in international collaborations. Focusing on institutional contributions, Canada’s University of Manitoba emerges as the foremost active entity, closely followed by the University of Pittsburgh in the United States. Because the prevalence of IBD patients is influenced by geographic location, ethnicity, and other factors, greater collaboration between national research institutions is necessary.^[26] A detailed examination of both country and institutional involvements reveals that while China and the United States are major contributors to this research domain, Canada boasts a significant number of scientific institutions advancing this field. Hence, it is recommended that Chinese researchers enhance their international collaborations to elevate the quality and influence of their research in the IBD and depression sphere.

Academic journals play an important role in the dissemination of knowledge and in shaping specific fields.^[27–29] Among the top 10 journals, “Inflammatory Bowel Diseases” published 50 papers, followed by “Journal of Crohn & Colitis” with 14, “Alimentary Pharmacology & Therapeutics” with 13, and “Journal of Pediatric Gastroenterology and Nutrition” also with 13. The journals mentioned above are more focused on the current state of research in the field and will also receive more attention from researchers who are furthering their understanding of the relationship between IBD and depression. Collectively, these 4 journals contributed to 22.9% of the total publications, signifying their prominence in the research of IBD and depression. Notably, “Inflammatory Bowel Diseases” stands out as the most frequently co-cited journal, garnering 1927 citations and amassing a total link strength of 33,093. This analysis positions “Inflammatory Bowel Diseases” as a highly influential and authoritative source in the realms of IBD and depression research.

Through our author analysis, we identified the authors of those articles with the highest number of published and co-cited articles. Figure 5 shows a visual map of authors and co-cited authors in the field. These visual maps offer valuable insights for identifying potential collaborators and illuminate the collaborative relationships between authors and co-citing authors in this field. The author with the most publications in this field is Bernstein CN. In a longitudinal cohort study, Bernstein CN research found that exacerbation of depressive symptoms was much more common in patients with active IBD than in patients with inactive disease.^[30] Standing out in this regard is Mikocka-Walus, A, who is the most frequently cited author with 245 citations. This highlights Mikocka-Walus, A’s comprehensive and authoritative contributions to this field. Our thorough examination of Mikocka-Walus, A’s research focus revealed primary interests in irritable bowel syndrome,^[31,32] CD,^[33,34] and aspects of mental health, particularly depression.^[35] His numerous publications in prestigious journals such as Lancet Gastroenterology & Hepatology, Nature Reviews Gastroenterology & Hepatology, and Gastroenterology attest to his significant influence in the realm of IBD and depression research. Mikocka-Walus, A’s work has notably advanced the field, showcasing his status as a leading figure in this area of study.

In the pool of 393 papers examined in this study, the 1 receiving the highest number of citations is “Symptoms of depression and anxiety are independently associated with clinical recurrence of inflammatory bowel disease,” featured in Clinical Gastroenterology and Hepatology.^[13] In this article, Mikocka-Walus, A suggested that psychological therapies should be included in the treatment program for patients with IBD. Researchers found that psychological therapies have a positive impact on alleviating depression and anxiety and improving quality of life in patients with IBD.^[32] It was closely followed by another influential paper, ‘Do antidepressants influence the disease course in IBD? A retrospective case-matched observational study’, published in Inflammatory Bowel Diseases.^[36] Studies have shown that the antidepressant paroxetine relieves UC by down-regulating multiple inflammatory pathways and modulating gut microbiota.^[37] Notably, the former article witnessed a citation surge between 2018 and 2021, while the latter had its peak between 2014 and 2017, underlining their significant impact in this research field. Furthermore, our analysis of citation bursts revealed that 3 articles from Inflammatory Bowel Diseases (with an impact factor of 4.9), Journal of Psychosomatic Research (impact factor 4.7), and Clinical Gastroenterology and Hepatology (impact factor 12.6) achieved citation burst strengths exceeding 10. This suggests a correlation between strong citation bursts and the quality of the articles, indicating that the impact factor of the publishing journal is not the sole determinant of an article’s influence.

Keywords analysis in this study provides insight into the primary focus areas of researchers within this field.^[38,39] Unsurprisingly, “IBD” and “depression” emerge as the most prevalent keywords. Among the 20 most frequently occurring keywords, other notable terms include “gut–brain axis,” “quality of life,” “fatigue,” and “mental health,” all of which are intricately linked to the study of IBD and depression.^[40] The evolution of research themes over time is evident in our timeline analysis. Scholars initially concentrated on subjects like “abdominal pain,” “disability,” and “antidepressant.” However, more recent trends show a shift towards “gut microbiota,” “epidemiology” and “macrophage,” signaling these as potential emerging hot topics. This shift indicates that future research directions in the study of IBD and depression might pivot towards exploring the intersections of gut microbiota, epidemiology and macrophage. Keyword citation burst indicates a sudden increase in the frequency of keywords within a short period of time, and analyzing the keyword citation burst can determine the research frontiers in the field and reflect the future research trends.^[41] The red line indicates the time from the beginning to the end of the keyword, and the blue line represents the year of the outbreak. The greater the intensity of a keyword’s outburst, the greater its impact. Of the top 12 keywords with the strongest citation bursts, 3 keywords had citation bursts that ended in 2020 or later. Thus, the 3 burst keywords, brain, major depression, and IBD reflect the latest research hotspots in the field.

5. Conclusion

To our knowledge, this study represents the inaugural comprehensive analysis of significant developments, research focal points, and upcoming directions in the study of IBD and depression. The focus of researchers has evolved from simply examining the association between the 2 conditions to delving into the underlying mechanisms that link them. In essence, this study encapsulates the progress and trends in IBD and depression research over the past decade, thereby laying the groundwork for future explorations in this domain.

6. Restriction

Although we have tried to ensure the normative nature of this study as much as possible, there are still some limitations. First, we screened relevant publications only from the WoSCC Database Science Citation Index Expanded and did not include publications from other databases. Secondly, the results of our initial search were not very satisfactory due to the broad nature of the search strategy, so we manually filtered the results of the initial search and therefore the literature included is somewhat subjective.

Author contributions

Conceptualization: Pengliang Liu, Yongchuang Zhang, Yucheng Li.

Data curation: Huang Huang.

Funding acquisition: Yucheng Li.

Project administration: Yucheng Li.

Software: Yongchuang Zhang.

Writing – original draft: Pengliang Liu.

Writing – review & editing: Pengliang Liu, Yucheng Li.