A systematic review with meta-analysis of the role of anxiety and depression in irritable bowel syndrome onset

The associated features of multiple somatic symptom complexes

OBJECTIVE

To assess whether two or more functional somatic symptom complexes (SSCs) showed stronger association with psychosocial correlates than single or no SSC after adjustment for depression/anxiety and general medical disorders.

METHODS

In a population-based sample we identified, by standardised questionnaire, participants with chronic widespread pain, chronic fatigue and irritable bowel syndrome, excluding those with a medical cause for pain/fatigue. We compared psychosocial variables in three groups: multiple (>1), single or no FSS, adjusting for depression/anxiety and general medical disorders using ordinal logistic regression. We evaluated whether multiple SSCs predicted health status 1 year later using multiple regression to adjust for confounders.

RESULTS

Of 1443 participants (58.0% response) medical records were examined in 990: 4.4% (n = 44) had 2 or 3 symptom complexes, 16.2% a single symptom complex. Many psychosocial adversities were significantly associated with number of SSCs in the expected direction but, for many, statistical significance was lost after adjustment for depression/anxiety and medical illness. Somatic symptoms, health anxiety, impairment and number of prior doctor visits remained significantly associated. Impaired health status 1 year later was predicted by multiple somatic symptom complexes even after adjustment for depression, anxiety, medical disorders and number of symptoms.

CONCLUSIONS

Depression, anxiety, medical illness and health anxiety, demonstrated an exposure-response relationship with number of somatic symptom complexes. These may be core features of all Functional Somatic Syndromes and may explain why number of somatic symptom complexes predicted subsequent health status. These features merit inclusion in prospective studies to ascertain causal relationships.

Irritable Bowel Syndrome and Depression: A Shared Pathogenesis

It is common knowledge that dysfunction of the immune and neuroendocrine systems, in addition to neuroplasticity, is among the pathways that underlie irritable bowel syndrome (IBS) and depression. From as early as the 1950s, the association of IBS with psychiatric disease was postulated; however, the exact mechanism remains elusive. There has been considerable research into the association of IBS and depression over the last years; research into the gut-brain axis and alterations in gut microbes have gained momentum to spell out the relationship between depression and IBS. Evidence from these researchers indicate the dysfunction of homeostatic coping mechanisms; corticotropin-releasing factor appears to be at the core of this dysfunction. The multifactorial etiology of both depression and IBS hinders a universal, one-strategy-fits-all treatment approach to patients with comorbid depression and IBS. This review analyzes the pathophysiology that associates these two conditions; it explores the bidirectional communication between the brain and the gastrointestinal tract, and how these influence the endocrine and immune systems. Review articles, clinical trials and randomized controlled trials that analyzed the association of depression and IBS were identified by searching PubMed, Google Scholar, and articles in PMC databases. Full texts written in English and available via these search engines were selected for the synthesis of this review. Alterations to the gut-brain axis, intestinal microbiota, and the neuro-immune system may be the cornerstone to the association of IBS and depression. This literature review opens alternate therapeutic approaches to comorbid IBS and depression and encourages further research into this topic.

Depressive symptoms in patients with irritable bowel syndrome: a meta-analysis of comparative studies

Depression is common in patients with irritable bowel syndrome (IBS), but the reported prevalence across different studies is inconsistent. This meta-analysis systematically examined the presence and severity of depressive symptoms in patients with IBS. Two investigators independently performed a literature search. The pooled depressive symptom severity was calculated using a random effects model. Subgroup, sensitivity and meta-regression analyses were conducted to examine the moderating factors of the development of depressive symptoms. Twenty four studies (n=2,837) comparing depressive symptoms between IBS patients (n=1,775) and healthy controls (n=1,062) were identified; 14 (58.3%) studies were rated as high quality. Compared to healthy controls, IBS patients had more frequent (OR=9.21, 95%CI: 4.56-18.57, P<0.001; I2=76%) and more severe depressive symptoms (n=1,480, SMD=2.02, 95%CI: 1.56-2.48, P<0.001; I2=94%). Subgroup analyses revealed that patients with all IBS subtypes had more severe depressive symptoms than controls. In addition, versions of the Hamilton Depression Rating Scale (HAM-D) and IBS diagnostic criteria were significantly associated with depressive symptom severity. Meta-regression analyses revealed that female gender, younger age and small sample size were significantly associated with more severe depressive symptoms. In conclusion, meta-analytic data showed that IBS patients had more frequent and severe depressive symptoms than healthy controls. Adequate screening and treatment for depression should be developed and implemented in this patient population.

The effect of fecal microbiota transplantation on psychiatric symptoms among patients with irritable bowel syndrome, functional diarrhea and functional constipation: An open-label observational study

BACKGROUNDS

The intestinal microbiota is considered as a potential common underpinning pathophysiology of Functional Gastrointestinal Disorders (FGIDs) and psychiatric disorders such as depression and anxiety. Fecal Microbiota Transplantation (FMT) has been reported to have therapeutic effects on diseases related to dysbiosis, but few studies have evaluated its effect on psychiatric symptoms.

METHODS

We followed 17 patients with either Irritable Bowel Syndrome (IBS), Functional Diarrhea (FDr) or Functional Constipation (FC) who underwent FMT for the treatment of gastrointestinal symptoms and observation of psychiatric symptoms. Changes in Hamilton Rating Scale for Depression (HAM-D) and subscale of sleep-related items, Hamilton Rating Scale for Anxiety (HAM-A) and Quick Inventory for Depressive Symptoms (QIDS) between baseline and 4 weeks after FMT, and relationship with the intestinal microbiota were measured.

RESULTS

At baseline, 12 out of 17 patients were rated with HAM-D ≥ 8. Significant improvement in HAM-D total and sleep subscale score, HAM-A and QIDS were observed (p = 0.007, p = 0.007, p = 0.01, p = 0.007, respectively). Baseline Shannon index indicated that microbiota showed lower diversity in patients with HAM-D ≥ 8 compared to those of healthy donors and patients with HAM-D < 8. There was a significant correlation between baseline Shannon index and HAM-D score, and a correlation between Shannon index change and HAM-D improvement after FMT.

LIMITATIONS

The small sample size with no control group.

CONCLUSIONS

Our results suggest that depression and anxiety symptoms may be improved by FMT regardless of gastrointestinal symptom change in patients with IBS, FDr and FC, and the increase of microbiota diversity may help to improve patient's mood.

Incidence of irritable bowel syndrome and chronic fatigue following GI infection: a population-level study using routinely collected claims data

OBJECTIVES

To investigate the occurrence of postinfectious IBS in routine outpatient care, comparing different types of GI infection and its interaction with psychosomatic comorbidity.

DESIGN

Retrospective cohort study using routinely collected claims data covering statutorily insured patients in Bavaria, Germany. Cases were defined as patients without prior record of functional intestinal disorder with a first-time diagnosis of GI infection between January 2005 and December 2013 and classed according to the type of infection. Each case was matched by age, sex and district of residence to a patient without history of GI infection. Prior psychological disorder (depression, anxiety or stress reaction disorder) was assessed in the 2 years prior to inclusion. Proportional hazards regression models were used to estimate the HRs for GI infection and psychological disorder. Chronic fatigue syndrome (CFS) was assessed as a comparator outcome.

RESULTS

A total of 508 278 patients with first diagnosis of GI infection were identified, resulting in a matched cohort of 1 016 556 patients. All infection types were associated with an increased risk of IBS (HR: 2.19-4.25) and CFS (HR 1.35-1.82). Prior psychological disorder was a distinct risk factor for IBS (HR: 1.73) and CFS (HR: 2.08). Female sex was a further risk factor for both conditions.

CONCLUSION

Psychological disorder and GI infections are distinct risk factors for IBS. The high incidence of non-specific GI infection suggests that postinfectious IBS is a common clinical occurrence in primary care. Chronic fatigue is a further significant sequela of GI infection.

Health problems associated with irritable bowel syndrome: analysis of a primary care registry

BACKGROUND

Associations between irritable bowel syndrome and other health problems have been described, but comprehensive reports are missing, especially in primary care.

AIMS

To investigate which health problems are associated with irritable bowel syndrome, how they cluster together and when they are typically diagnosed relative to irritable bowel syndrome.

METHODS

We used Intego, a general practice registry in Flanders, Belgium. Patients with an irritable bowel syndrome diagnosis (n = 13 701) were matched with controls without gastrointestinal diagnosis and controls with organic gastrointestinal disease. Long-term prevalences of 680 symptoms and diagnoses were compared between patients and controls. Results were summarised using functional enrichment analysis and visualised in a network and we calculated incidence rate ratios in the 10 years before and after the irritable bowel syndrome diagnosis for the network's key components.

RESULTS

Various symptoms and infections, but not neoplasms, were enriched in irritable bowel syndrome patients compared to both control groups. We characterised the comorbidities of irritable bowel syndrome as psychosocial health problems, urogenital symptoms and infections, musculoskeletal symptoms and other somatic symptoms. These had a uniform incidence in the years around the irritable bowel syndrome diagnosis, and did not structurally precede or follow irritable bowel syndrome.

CONCLUSIONS

Irritable bowel syndrome shares long-term associations with psychosocial health problems, urogenital symptoms and infections, musculoskeletal symptoms and other somatic symptoms in primary care. Clinicians are encouraged to take comorbidities into account when diagnosing and managing irritable bowel syndrome, as this may have important treatment implications.

Positive and negative affect mediate the bidirectional relationship between emotional processing and symptom severity and impact in irritable bowel syndrome

INTRODUCTION

Individuals with IBS report higher levels of psychological distress compared to healthy controls. Distress has been associated with emotional processing difficulties but studies have not explored how the relationship between distress and emotional processing affects IBS. There is little research on the role of positive affect (PA) in IBS.

AIMS

(a) If difficulties in self-reported emotional processing are associated with affect and IBS measures (i.e., symptom severity, interference in life roles) (b1) If affect mediates the relationship between emotional processing and IBS measures (b2) Alternative model: if affect mediates the relationship between IBS and emotional processing (c) If PA moderates the relationship between distress and IBS.

METHODS

Participants with a confirmed diagnosis of IBS (n=558) completed a questionnaire including measures of emotional processing (i.e., unhelpful beliefs about negative emotions, impoverished emotional experience), distress, PA, and IBS symptoms/interference. Mediation and moderation analyses were conducted with Maximum Likelihood Estimation.

RESULTS

Distress and PA mediated or partly mediated the relationship between unhelpful beliefs about negative emotions/impoverished emotional experience and both IBS measures. The alternative models were also valid, suggesting a two-way relationship between emotional processing and IBS through affect. PA did not moderate the relationship between distress and IBS.

CONCLUSION

Future interventions in IBS may benefit from not only targeting the management of physical symptoms and their daily impact but also aspects related to the experience of both negative and positive affect, and the acceptance and expression of negative emotions. Longitudinal studies are needed to confirm causal relationships within the explored models.

General practitioners' perceptions of irritable bowel syndrome: a Q-methodological study

BACKGROUND

Irritable bowel syndrome (IBS) is a common disorder that imposes a significant burden upon societies, health care and quality of life, worldwide. While a diverse range of patient viewpoints on IBS have been explored, the opinions of the GPs they ideally need to develop therapeutic partnerships with are less well defined.

OBJECTIVE

To explore how GPs perceive IBS, using Q-methodology, which allows quantitative interpretation of qualitative data.

DESIGN AND SETTING

A Q-methodological study of GPs in Leeds, UK.

METHOD

Thirty-three GPs completed an online Q-sort in which they ranked their level of agreement with 66 statements. Factor analysis of the Q-sorts was performed to determine the accounts that predominated in understandings of IBS. Ten of the GPs were interviewed in person and responses to the statements recorded to help explain the accounts.

RESULTS

Analysis yielded one predominant account shared by all GPs-that IBS was a largely psychological disorder. This account overshadowed a debate represented by a minority, polarized between those who viewed IBS as almost exclusively psychological, versus those who believed IBS had an organic basis, with a psychological component. The overwhelming similarity in responses indicates that all GPs shared a common perspective on IBS. Interviews suggested degrees of uncertainty and discomfort around the aetiology of IBS.

CONCLUSION

There was overwhelming agreement in the way GPs perceived IBS. This contrasts with the range of patient accounts of IBS and may explain why both GPs and their patients face difficult negotiations in achieving therapeutic relationships.

Fatty acid components in Asian female patients with irritable bowel syndrome

Abdominal pain is one of the key symptoms of irritable bowel syndrome (IBS). Studies have indicated an increase in the incidence of IBS in Asia. However, yet the pathophysiology of this disease remains unknown. Women are more likely to develop the condition than men, especially the constipation-predominant type. Essential fatty acid (EFA) malnutrition is one of several theories discussing the mechanism of IBS.The authors hypothesized that significant EFA deficiency may cause abdominal pain in patients with IBS. However, because patterns in the oral intake of EFAs differ between cultures, the authors narrowed this study to examine the nutritional status of Asian female patients with IBSThe authors investigated Asian female patients with IBS and compared them with a group of healthy controls. Thirty patients with IBS and 39 healthy individuals were included in this study. The participants' age, height, weight, and waist size were recorded. The 24-item Hamilton Depression Rating Scale was documented. Both erythrocyte and plasma fatty acid content were analyzed through gas-liquid chromatography.The authors found that patients with IBS exhibited significantly higher scores for depression, higher proportions of plasma saturated fatty acids and monounsaturated fatty acids, and lower proportions of docosahexaenoic acid and total omega-3 polyunsaturated fatty acids in plasma are associated with IBS in Asian female patients. Further study is indicated to confirm the causality of this association.

Irritable Bowel Syndrome and Stress-Related Psychiatric Co-morbidities: Focus on Early Life Stress

Irritable bowel syndrome is a functional gastrointestinal disorder, with stress playing a major role in onset and exacerbation of symptoms such as abdominal pain and altered bowel movements. Stress-related disorders including anxiety and depression often precede the development of irritable bowel syndrome and vice versa. Stressor exposure during early life has the potential to increase an individual's susceptibility to both irritable bowel syndrome and psychiatric disease indicating that there may be a common origin for these disorders. Moreover, adverse early life events significantly impact upon many of the communication pathways within the brain-gut-microbiota axis, which allows bidirectional interaction between the central nervous system and the gastrointestinal tract. This axis is proposed to be perturbed in irritable bowel syndrome and studies now indicate that dysfunction of this axis is also seen in psychiatric disease. Here we review the co-morbidity of irritable bowel syndrome and psychiatric disease with their common origin in mind in relation to the impact of early life stress on the developing brain-gut-microbiota axis. We also discuss the therapeutic potential of targeting this axis in these diseases.

The role of high expectations of self and social desirability in emotional processing in individuals with irritable bowel syndrome: A qualitative study

OBJECTIVES

Although high levels of distress are associated with the onset and severity of Irritable bowel syndrome (IBS), it is unclear how this relates to emotional processing, particularly in relation to maintenance of symptoms and treatment outcome. This qualitative study embedded within a randomized controlled trial aimed to explore how individuals with refractory IBS experience, express, and manage their emotions after either therapist-delivered cognitive behavioural therapy (TCBT) or Web-based CBT (WBCBT) compared to treatment as usual (TAU).

DESIGN

Cross-sectional qualitative study.

METHODS

Fifty-two semi-structured interviews were conducted at post-treatment with 17 TCBT, 17 WBCBT, and 18 TAU participants. The transcripts were analysed using inductive thematic analysis with grounded theory elements. NVivo 11 was used to compare themes across groups.

RESULTS

Across all groups, high expectations of self was a recurring reason for how participants experienced and expressed their emotions. Three themes with subthemes captured how high expectations related to specific aspects of emotional processing: perceived causes of emotions, strategies for coping with emotions (bottling up, avoiding emotions, and active coping strategies), and the perceived interplay between emotions and IBS symptoms.

CONCLUSIONS

Patients recognized that their IBS symptoms both triggered and were triggered by negative emotions. However, there was a tendency to bottle up or avoid negative emotions for reasons of social desirability regardless of whether patients had CBT for IBS or not. Future psychological interventions in IBS may benefit from addressing negative beliefs about expressing emotions, promoting assertive emotional expression, and encouraging the experience of positive emotions. Statement of contribution What is already known on this subject? High levels of distress are consistently associated with both the onset and maintenance of IBS symptoms. Little is known about how this relates to the concept of emotional processing. Preliminary findings suggest a positive correlation between poor emotional processing and IBS. However, further studies need to confirm its role in relation to aetiology, maintenance of symptoms, and response to treatment. What does this study add? High expectations of self and social desirability seem to be important aspects shaping the way individuals with IBS experience, express, and manage their emotions. Emotional avoidance and bottling up were reported as key strategies to cope with negative emotions. The study revealed that bottling up is not perceived as an all-or-nothing strategy but can be applied selectively depending on the context. Psychological interventions in IBS may benefit from addressing not only illness-related causes of negative emotions but also personal and social triggers of distress.

Fecal metagenomic profiles in subgroups of patients with myalgic encephalomyelitis/chronic fatigue syndrome

BACKGROUND

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained persistent fatigue, commonly accompanied by cognitive dysfunction, sleeping disturbances, orthostatic intolerance, fever, lymphadenopathy, and irritable bowel syndrome (IBS). The extent to which the gastrointestinal microbiome and peripheral inflammation are associated with ME/CFS remains unclear. We pursued rigorous clinical characterization, fecal bacterial metagenomics, and plasma immune molecule analyses in 50 ME/CFS patients and 50 healthy controls frequency-matched for age, sex, race/ethnicity, geographic site, and season of sampling.

RESULTS

Topological analysis revealed associations between IBS co-morbidity, body mass index, fecal bacterial composition, and bacterial metabolic pathways but not plasma immune molecules. IBS co-morbidity was the strongest driving factor in the separation of topological networks based on bacterial profiles and metabolic pathways. Predictive selection models based on bacterial profiles supported findings from topological analyses indicating that ME/CFS subgroups, defined by IBS status, could be distinguished from control subjects with high predictive accuracy. Bacterial taxa predictive of ME/CFS patients with IBS were distinct from taxa associated with ME/CFS patients without IBS. Increased abundance of unclassified Alistipes and decreased Faecalibacterium emerged as the top biomarkers of ME/CFS with IBS; while increased unclassified Bacteroides abundance and decreased Bacteroides vulgatus were the top biomarkers of ME/CFS without IBS. Despite findings of differences in bacterial taxa and metabolic pathways defining ME/CFS subgroups, decreased metabolic pathways associated with unsaturated fatty acid biosynthesis and increased atrazine degradation pathways were independent of IBS co-morbidity. Increased vitamin B6 biosynthesis/salvage and pyrimidine ribonucleoside degradation were the top metabolic pathways in ME/CFS without IBS as well as in the total ME/CFS cohort. In ME/CFS subgroups, symptom severity measures including pain, fatigue, and reduced motivation were correlated with the abundance of distinct bacterial taxa and metabolic pathways.

CONCLUSIONS

Independent of IBS, ME/CFS is associated with dysbiosis and distinct bacterial metabolic disturbances that may influence disease severity. However, our findings indicate that dysbiotic features that are uniquely ME/CFS-associated may be masked by disturbances arising from the high prevalence of IBS co-morbidity in ME/CFS. These insights may enable more accurate diagnosis and lead to insights that inform the development of specific therapeutic strategies in ME/CFS subgroups.

The association of catastrophizing with quality-of-life outcomes in patients with irritable bowel syndrome

Background

Catastrophizing is a cognitive process characterized by a propensity to concentrate on and magnify the value of an actual or anticipated painful stimulus and negatively assesses one’s ability to cope. Catastrophizing is an important predictor of pain-related outcomes. A cornerstone symptom of irritable bowel syndrome (IBS) is abdominal pain or discomfort. Also individuals with IBS have been reported to have a tendency to catastrophize. In a sample of individuals who suffer from IBS, we hypothesized that those individuals who catastrophize (catastrophizers) would have worse outcomes as compared to those who do not catastrophize (non-catastrophizers).

Methods

One hundred and one adults with IBS (79% female, mean age 42 years, 97% Caucasian) were recruited from outpatient clinics and data were collected through self-report measures. Catastrophizing was measured with the catastrophizing subscale of the Coping Strategies Questionnaire, illness representations were measured with The Revised Illness Perception Questionnaire (IPQ-R), psychological distress was measured with the Brief Symptom Inventory 18 (BSI-18), and health-related quality of life was measured using the Irritable Bowel Syndrome-Quality of Life (IBS-QOL) measure. Descriptive statistics, correlations, and multiple linear regression analyses were completed to describe participants, the associations of the variables of interest, and the unique relationship between psychosocial variables and HRQOL.

Results

Overall, participants reported poor HRQOL (M = 63.32, range 0–100). Catastrophizers differed significantly on IBS-QOL from non-catastrophizers (M = 48.98 vs. non-catastrophizers M = 78.53; p < 0.001), BSI-18 (M = 21.35 vs. non-catastrophizers M = 6.76; p < 0.001), and IPQ-R, specifically the consequences (M = 21.75 vs. non-catastrophizers M = 17.20; p < 0.001) and emotional representations (M = 20.90 vs. non-catastrophizers M = 15.43; p < 0.001). Catastrophizing was positively correlated with the consequences (r = .54; p < 0.01) and emotional representations (r = .65; p < 0.01) and negatively correlated with total HRQOL (r = −0.76; p < 0.01).

Conclusion

The findings indicated that participants who catastrophized reported worse psychosocial and functional outcomes. Thus, catastrophizing, in addition to psychological distress variables, may be an important factor to address in optimizing health outcomes in individuals with IBS. In addition, illness perceptions were strongly related to catastrophizing and HRQOL; assessment and integration of illness perceptions as well as catastrophizing into the management of individuals who suffer with IBS may maximize the health outcomes.

Gastrointestinal Pharmacology

There is little evidence for most of the medications currently used to treat functional abdominal pain disorders (FAPDs) in children. Not only are there very few clinical trials, but also most have significant variability in the methods used and outcomes measured. Thus, the decision on the most appropriate pharmacological treatment is frequently based on adult studies or empirical data. In children, peppermint oil, trimebutine, and drotaverine have shown significant benefit compared with placebo, each of them in a single randomized clinical trial. A small study found that cyproheptadine was beneficial in the treatment of FAPDs in children. There are conflicting data regarding amitriptyline. While one small study found a significant benefit in quality of life compared with placebo, a large multicenter study found no benefit compared with placebo. The antidepressant, citalopram, failed to meet the primary outcomes in intention-to-treat and per-protocol analysis. Rifaximin has been shown to be efficacious in the treatment of adults with IBS. Those findings differ from studies in children where no benefit was found compared to placebo. To date, there are no placebo-controlled trials published on the use of linaclotide or lubiprostone in children. Alpha 2 delta ligands such as gabapentin and pregabalin are sometimes used in the care of this group of children, but no clinical trials are available in children with FAPDs. Similarly, novel drugs that have been approved for the care of irritable bowel with diarrhea in adults such as eluxadoline have yet to be studied in children.

CONCLUSIONS

Little data support the use of most medications commonly used to treat FAPDs in children. More randomized, placebo-controlled studies are needed to assess the efficacy of pharmacological interventions in the treatment of FAPDs in children.

Long-term bicycle riding ameliorates the depression of the patients undergoing hemodialysis by affecting the levels of interleukin-6 and interleukin-18

PURPOSE

Hemodialysis patients with depression have a higher risk of death and hospitalization. Although there is pharmacological management for the depression of hemodialysis patients, the adverse effect of the drug limits the use. The nonpharmacological way, bicycle riding, may be an effective way for the therapy of the depression in hemodialysis patients. However, the underlying mechanism of this relationship is still not fully explained, while interleukin-6 (IL-6) and interleukin-18 (IL-18) are associated with depression and exercise. Thus, the effects of bicycle riding on the levels of the interleukin were explored.

PARTICIPANTS AND METHODS

One hundred and eighty-nine patients with chronic hemodialysis were selected and randomly assigned to three groups of medicine (MG, received 20-mg escitalopram daily), medicine and aerobic exercise (MAG, received 20-mg escitalopram daily and bicycle riding six times weekly), and only aerobic exercise (AG, received 20-mg placebo daily and bicycle riding six times weekly). The whole experiment lasted for 18 weeks. The quality of life (36-Item Short Form Health Survey) and depression severity according to criteria in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM-IV] were measured before and at the end of this study. The serum levels of IL-6 and IL-18 were measured by an enzyme-linked immunosorbent assay kit.

RESULTS

The quality of life was improved and depression severity was reduced significantly in the MAG and AG groups when compared with the MG group (P<0.05). Serum levels of IL-6 and IL-18 were the highest in the MG group, moderate in the MAG group and the lowest in AG group. On the other hand, the serum levels of IL-6 and IL-18 were closely associated with depression scores (P<0.05).

CONCLUSION

Aerobic exercise improves the quality of life and ameliorates the depression severity of the patients undergoing hemodialysis by affecting the levels of IL-6 and IL-18. Bicycle riding is a potential way for the depression therapy of the patients with chronic hemodialysis.