Experience with anxiety and depression treatment studies: implications for designing irritable bowel syndrome clinical trials

Anxiety-Related Factors Associated With Symptom Severity in Irritable Bowel Syndrome in Jazan, Saudi Arabia

BACKGROUND

 This study in Jazan, Saudi Arabia aims to identify anxiety-related factors associated with symptom severity in irritable bowel syndrome (IBS). IBS is a common gastrointestinal disorder causing abdominal pain and altered bowel habits. The prevalence of IBS in Saudi Arabia is estimated to be 10%-20% among the general population. Therefore, the present study aimed to determine anxiety-related factors associated with symptom severity in irritable bowel syndrome in Jazan, Saudi Arabia. Understanding these factors will provide insights into the overall impact of IBS on patients' quality of life.

METHODS

The study utilized a cross-sectional, descriptive observational design to examine the general population in Jazan, Saudi Arabia. The sample size of 385 individuals was calculated based on the population size and desired error margin. A convenience sampling technique was employed to select participants who met the inclusion criteria. A validated anonymous self-administered electronic survey was distributed through social media channels. The survey consisted of four sections gathering demographic information, personal risk factors, IBS types with anxiety and risk factors, and a questionnaire to determine the level of anxiety. A pilot study was conducted to improve the survey's clarity. Ethical considerations were followed, and data were analyzed using Statistical Package for Social Sciences (SPSS; IBM Corp., Armonk, NY, USA). Descriptive statistics and significance tests were performed.

RESULT

A study with 637 participants found a 31.08% prevalence of IBS, which was more common in females. Participants with IBS had a higher rate of chronic disease. There were no significant differences in demographic factors between IBS and non-IBS participants. The duration of IBS diagnosis varied, with the majority of IBS with diarrhea (IBS-D) sufferers being diagnosed five years prior. Symptom severity differed among IBS types, with those with an unspecified type reporting the highest percentage of severe symptoms. IBS types were also correlated with anxiety levels, with IBS-D sufferers reporting moderate anxiety and those with an unspecified type reporting severe anxiety.

CONCLUSION

A study with 637 participants found the prevalence of IBS to be 31.08%, with higher rates in females. IBS was associated with chronic diseases and higher anxiety levels. The findings emphasize the need for comprehensive management of IBS, including psychological interventions and dietary modifications, to improve patients' overall health and quality of life. Further research on genetic and modifiable risk factors is needed.

The impact of posttraumatic stress disorder on upper gastrointestinal investigations in Australian Defence Force veterans: a retrospective review

Veterans with posttraumatic stress disorder (PTSD) commonly exhibit associated gastrointestinal (GI) symptoms. We compared upper GI endoscopy and abdominal ultrasound rates in veterans with and without PTSD. Veterans with PTSD were 77-81% more likely to undergo these procedures than those without PTSD. PTSD symptomatology influences GI investigation rate and more emphasis on clinician and patient education is recommended regarding stress-related gut symptoms.

Somatization is associated with altered serum levels of vitamin D, serotonin, and brain-derived neurotrophic factor in patients with predominant diarrhea irritable bowel syndrome

BACKGROUND

Patients with irritable bowel syndrome (IBS) often show psychological disorders, including somatization, usually driven by an altered gut-brain axis. These changes are also accompanied by modifications in the circulating levels of vitamin D (VD) and neurotransmitters such as serotonin (5-HT) and brain-derived neurotrophic factor (BDNF). The present study aimed to evaluate the relationship between gastrointestinal (GI) symptoms and circulating levels of VD, 5-HT, and BDNF in IBS patients with diarrhea (IBS-D) categorized according to somatization.

METHODS

Fifty-three IBS-D patients were recruited and profiled for GI symptoms by validated questionnaires. The fasting serum concentrations of VD, 5-HT, and BDNF were assessed. The health of the intestinal barrier, minimal inflammation, and dysbiosis was also evaluated.

KEY RESULTS

Thirty patients showed high somatization scores, IBS-D(S+), and 23 low somatization scores, IBS-D(S-). IBS-D(S+) patients reported higher "Abdominal pain" and the "Abdominal pain duration in days" scores, lower serum VD levels and increased 5-HT and BDNF concentrations than IBS-D(S-). Besides, in IBS-D(S+) patients, the GI symptoms correlated with 5HT, BDNF, and VD concentrations. These parameters were associated with impaired small intestinal permeability and increased inflammation markers.

CONCLUSIONS AND INFERENCES

These data support the multifactorial IBS pathogenesis in which organic and psychological factors interact. An active role by VD, 5-HT, and BDNF in affecting the clinical and biochemical profiles in IBS-D(S+) patients may be conceivable. Therefore, the routine VD estimation and the assay of circulating levels of 5-HT and BDNF could be considered a new approach for managing these patients.

Hypnotherapy and IBS: Implicit, long-term stress memory in the ENS?

The association between irritable bowel syndrome (IBS) and psychiatric and mood disorders may be more fundamental than was previously believed. Prenatal, perinatal, postnatal, and early-age conditions can have a key role in the development of IBS. Subthreshold mental disorders (SMDs) could also be a significant source of countless diverse diseases and may be a cause of IBS development. We hypothesize that stress-induced implicit memories may persist throughout life by epigenetic processes in the enteric nervous system (ENS). These stress-induced implicit memories may play an essential role in the emergence and maintenance of IBS. In recent decades, numerous studies have proven that hypnosis can improve the primary symptoms of IBS and also reduce noncolonic symptoms such as anxiety and depression and improve quality of life and cognitive function. These significant beneficial effects of hypnosis on IBS may be because hypnosis allows access to unconscious brain processes.

Somatization in patients with predominant diarrhoea irritable bowel syndrome: the role of the intestinal barrier function and integrity

Background

Irritable bowel syndrome (IBS) is characterised by gastrointestinal (GI) and psychological symptoms (e.g., depression, anxiety, and somatization). Depression and anxiety, but not somatization, have already been associated with altered intestinal barrier function, increased LPS, and dysbiosis. The study aimed to investigate the possible link between somatization and intestinal barrier in IBS with diarrhoea (IBS-D) patients.

Methods

Forty-seven IBS-D patients were classified as having low somatization (LS = 19) or high somatization (HS = 28) according to the Symptom Checklist-90-Revised (SCL-90-R), (cut-off score = 63). The IBS Severity Scoring System (IBS-SSS) and the Gastrointestinal Symptom Rating Scale (GSRS) questionnaires were administered to evaluate GI symptoms. The intestinal barrier function was studied by the lactulose/mannitol absorption test, faecal and serum zonulin, serum intestinal fatty-acid binding protein, and diamine oxidase. Inflammation was assessed by assaying serum Interleukins (IL-6, IL-8, IL-10), and tumour necrosis factor-α. Dysbiosis was assessed by the urinary concentrations of indole and skatole and serum lipopolysaccharide (LPS). All data were analysed using a non-parametric test.

Results

The GI symptoms profiles were significantly more severe, both as a single symptom and as clusters of IBS-SSS and GSRS, in HS than LS patients. This finding was associated with impaired small intestinal permeability and increased faecal zonulin levels. Besides, HS patients showed significantly higher IL-8 and lowered IL-10 concentrations than LS patients. Lastly, circulating LPS levels and the urinary concentrations of indole were higher in HS than LS ones, suggesting a more pronounced imbalance of the small intestine in the former patients.

Conclusions

IBS is a multifactorial disorder needing complete clinical, psychological, and biochemical evaluations.

Trial registration: https://clinicaltrials.gov/ct2/show/NCT03423069.

Psychiatric Co-morbidity in Patients With Irritable Bowel Syndrome at a Tertiary Care Center in Northern India

Background/Aims

Irritable bowel syndrome (IBS) is a chronic psycho-physiological disorder. It is considered to be the most common functional gastrointestinal disorder, and about 50–90% of IBS patients have associated psychiatric co-morbidity. We aimed to study psychiatric co-morbidities in patients with IBS visiting a tertiary care center.

Methods

This was a cross-sectional case-control study conducted over a duration of one and a half years from January 2014 to July 2015. Patients were selected from the out-patient department of gastroenterology. About 160 patients with IBS who fulfilled the inclusion criteria and who gave written informed consent were selected as study cases. The healthy attendants of cases were selected as controls. A total of 200 controls were selected. Rome-III criteria were used to diagnose IBS. For diagnosing psychiatric disorders, we used the Mini International Neuropsychiatric Interview Schedule Plus.

Results

Mean age of our cases and controls was 39.7 ± 11.4 and 37.7 ± 9.6 years, respectively. Females outnumbered males in our cases as well as their controls by a ratio of 2:1 approximately. Psychiatric disorders were seen in 84.4% of IBS patients as compared to 41.5% in controls. Major psychiatric disorders seen in our patients were generalized anxiety disorders (30.0%) and depression (28.0%).

Conclusions

The majority of patients with IBS who present to a tertiary care center have co-morbid psychiatric disorders. We need to screen these patients for such co-morbidities and develop a holistic approach for better outcome in such cases.

Common Mechanism of Pathogenesis in Gastrointestinal Diseases Implied by Consistent Efficacy of Single Chinese Medicine Formula: A PRISMA-Compliant Systematic Review and Meta-Analysis

Gastrointestinal (GI) disorders often manifest similar symptoms with overlapping clinical diagnosis and unmet medical needs. Traditional Chinese medicine (TCM) has history-proven benefits for GI diseases; albeit language barrier prevents Western readers from accessing the original reports in Chinese. The TCM formula Si-Ni-San (SNS) consists of 4 herbs targeting on homeostatic disturbances characterized by "reflux" and "irritable" problems. Here we used SNS as a therapeutic tool to explore the common mechanisms of pathogenesis in non-neoplastic GI diseases.Data sources from PUBMED, Chinese National Knowledge Infrastructure, and Wanfang databases were searched for clinical trials. Comparisons were SNS as intervention and Western conventional medicine as control, which treat patients with upper GI disorders (gastroesophageal reflux disease, peptic ulcer, chronic gastritis, duodenogastric reflux), lower GI diseases (irritable bowel syndrome, ulcerative colitis), and functional dyspepsia. Participants and studies in accordance with the Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement were eligible. We used the Jadad scale to assess methodological qualities, the fixed or random-effect model to evaluate therapeutic efficacy, and the funnel plots to explore publication bias. Outcome was clinical efficacy defined by symptom relief with normal GI endoscopy, radiology, and pathology.We included 83 studies involving 7762 participants: 1708 versus 1397 of the upper GI disorders in 34 studies, 901 versus 768 of the lower GI diseases in 19 studies, 1641 versus 1348 of functional dyspepsia in 30 studies, and 328 versus 287 of relapse rate in 8 studies. Six studies had a Jadad score >2 points and the rest were <2 points. Pooled data showed significant efficacy of SNS for the upper GI disorders (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 3.09-4.92), lower GI diseases (OR = 4.91, 95% CI = 3.71-6.51), and functional dyspepsia (N = 2989; OR = 3.94, 95% CI = 3.17-4.90). The relapse rate was 12.9% for SNS, significantly <46.5% for conventional therapies (OR = 0.16, 95% CI = 0.11-0.25).The consistent efficacy of the single TCM formula implicates common mechanisms of pathogenesis in GI disorders.

Psychological features in patients with and without irritable bowel syndrome: A case-control study using Symptom Checklist-90-Revised

CONTEXT

Recent studies have demonstrated that a high proportion of irritable bowel syndrome (IBS) patients shows an association with psychological factors. A few studies were conducted on the investigation of psychological features of IBS patients in Iran.

AIMS

We aimed to evaluate the relationship of psychological distress with IBS in outpatient subjects.

SETTINGS AND DESIGN

A total of 153 consecutive outpatients met Rome III criteria, and 163 controls were interred to study and invited to complete the Symptom Checklist-90-Revised (SCL-90-R) instrument in order to assessment of psychological distress.

STATISTICAL ANALYSIS

Univariate (t-test and Chi-square) and multivariate (logistic regression) methods were used for data analysis.

RESULTS

A significant association of IBS with all nine subscale and three global indices including global severity index (GSI), positive symptom distress index (PSDI), and positive symptom total (PST) of the SCL-90-R were detected. Patients with IBS reported significantly higher levels of poor appetite, trouble falling asleep, thoughts of death or dying, early morning awakening, disturbed sleep, and feelings of guilt compared to the controls. Multivariate analysis indicated that interpersonal sensitivity, somatization, paranoid ideation, depression and phobic anxiety subscales, and PST, PSDI, and GSI global indices were significantly associated with IBS (age, gender, educational level, marital status, employment status, smoking, alcohol use, and body mass index).

CONCLUSIONS

Psychological features are strongly associated with IBS; notably, interpersonal sensitivity, somatization, paranoid ideation, depression, phobic anxiety, and all global indices including PST, PSDI, and GSI is significantly associated with. Hence, the appropriate psychological assessment in these patients is critically important.

A mixed methods feasibility study to evaluate the use of a low-intensity, nurse-delivered cognitive behavioural therapy for the treatment of irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is characterised by symptoms such as abdominal pain, constipation, diarrhoea and bloating. These symptoms impact on health-related quality of life, result in excess service utilisation and are a significant burden to healthcare systems. Certain mechanisms which underpin IBS can be explained by a biopsychosocial model which is amenable to psychological treatment using techniques such as cognitive behavioural therapy (CBT). While current evidence supports CBT interventions for this group of patients, access to these treatments within the UK healthcare system remains problematic.

METHODS AND ANALYSIS

A mixed methods feasibility randomised controlled trial will be used to assess the feasibility of a low-intensity, nurse-delivered guided self-help intervention within secondary care gastrointestinal clinics. A total of 60 participants will be allocated across four treatment conditions consisting of: high-intensity CBT delivered by a fully qualified cognitive behavioural therapist, low-intensity guided self-help delivered by a registered nurse, self-help only without therapist support and a treatment as usual control condition. Participants from each of the intervention arms of the study will be interviewed in order to identify potential barriers and facilitators to the implementation of CBT interventions within clinical practice settings. Quantitative data will be analysed using descriptive statistics only. Qualitative data will be analysed using a group thematic analysis.

ETHICS AND DISSEMINATION

This study will provide essential information regarding the feasibility of nurse-delivered CBT interventions within secondary care gastrointestinal clinics. The data gathered during this study would also provide useful information when planning a substantive trial and will assist funding bodies when considering investment in substantive trial funding. A favourable opinion for this research was granted by the Nottingham 2 Research Ethics Committee.

TRIAL REGISTRATION NUMBER ISRCTN

83683687 (http://www.controlled-trials.com/ISRCTN83683687).

An open-label trial of duloxetine in patients with irritable bowel syndrome and comorbid generalized anxiety disorder

OBJECTIVE

Irritable bowel syndrome (IBS) is commonly comorbid with generalized anxiety disorder (GAD). We evaluated whether duloxetine would lead to improvement in symptoms and quality of life in patients with both conditions.

METHOD

A 12-week, open-label trial of duloxetine was conducted in 13 subjects with IBS and GAD. The primary outcome measure was the Clinical Global Impression (CGI) Scale. Secondary measures included the Hamilton Anxiety Rating Scale, IBS Quality of Life (IBS-QOL) Scale, and IBS Symptom Severity Scale (IBS-SSS).

RESULTS

Repeated measures ANOVA was used to examine the effect of treatment with duloxetine on ratings of anxiety and IBS. Significant improvement was observed on the CGI-Improvement (F = 14.19, df = 1,12, p < 0.001) and Severity scales (F = 16.16, df = 1,12, p < 0.001). Secondary measures revealed significant reduction in symptoms of anxiety (F = 11.66, df = 1,12, p < 0.01), ηp(2) = 0.56, and IBS-SSS (F = 6.05, df = 1,12, p < 0.001), ηp(2) = 0.34, in addition to IBS-QOL improvements (F = 11.66, df = 1,12, p < 0.01), ηp(2) = 0.56.

CONCLUSION

Results of this pilot study support the efficacious use of duloxetine in comorbid IBS and GAD. Participants reported significant reductions in IBS components, as well as improvement in GAD.

Prevalence of depression and anxiety in irritable bowel syndrome: A clinic based study from India

BACKGROUND

Irritable Bowel Syndrome (IBS) is a very common gastrointestinal dysfunction. Despite strong evidence of high prevalence of depression and anxiety in IBS there is very limited research on this in India.

MATERIALS AND METHODS

Cases of IBS and controls with non-ulcerative dyspepsia were recruited from a gastroenterology clinic in Mumbai, India. Presence of anxiety disorder and depression were assessed by using the Hamilton Anxiety rating scale and Hamilton Depression rating scale respectively. Prevalence rates of anxiety and depression were established and Odds Ratio (OR) was calculated to determine the association of depression and anxiety disorders with IBS.

RESULTS

In IBS cases, the prevalence of depression and anxiety disorder was 37.1% and 31.4% respectively. In patients with IBS the OR for depression was 6.3 (95% CI 1.6-24.74, P=0.009) and the OR for anxiety disorder was 7.56 (95% CI 1.53-37.29, P=0.01).

CONCLUSION

The prevalence of depression and anxiety disorder in IBS is very high. Therefore, screening of IBS patients for anxiety and depression would facilitate better interventions and consequently better outcomes.

Ferulic acid-induced anti-depression and prokinetics similar to Chaihu-Shugan-San via polypharmacology

Selective serotonin reuptake inhibitors (SSRIs), one of popular antidepressants as "one-compound-one-target" paradigm, cannot but discontinue because of inhibiting gut movement. Traditional Chinese medicine (TCM) Chaihu-Sugan-San (CSS) can simultaneously exert anti-depression and prokinetics. From this thread, we aimed to find a new antidepressant with polypharmacological mechanisms. In vivo antidepressive and prokinetic comparisons between CSS and its absorbed compound ferulic acid (FA) were made. And FA's action mechanisms involved in monoaminergic systems, HPA axis and gastrointestinal peptide ghrelin was then studied in forced swimming test (FST) of rat. Lastly, the jejunal contraction activity evoked by FA was measured in vitro. Compared with vehicle, FA reduced immobility time, increased locomotor activity, accelerated gastric emptying and intestinal transit similar to CSS whose absorbable component FA was identified in hippocampus and jejunum. FA's prokinetics in vivo was further supported by its jejunal contraction in vitro. FA-induced anti-immobility was prevented by pretreated with PCPA, WAY-100635, ketanserin, sulpiride, SCH233390, haloperidol and yohimbine, respectively. CRH, ACTH and 5-HT were significantly decreased, but ghrelin was apparently increased compared with vehicle. In summary, FA induced anti-depression and prokinetics similar to CSS via inhibiting serotonin, norepinephrine and dopamine reuptakes, regulating HPA axis, increasing ghrelin and stimulating jejunal contraction simultaneously.

Cognitive-behavioral treatment of persistent functional somatic complaints and pediatric anxiety: an initial controlled trial

BACKGROUND

Children and adolescents who seek medical treatment for persistent physical distress often suffer from co-occurring anxiety disorders. Treatment options for this impaired population are limited. This study tests the feasibility and potential efficacy of a cognitive-behavioral intervention targeting pain and anxiety for youth with impairing functional physical symptoms and anxiety disorders presenting to pediatricians for medical care.

METHODS

Children and adolescents (aged 8-16) experiencing somatic complaints, without an explanatory medical disorder (i.e., functional), were recruited from primary care and specialty (gastroenterologists and cardiologists) pediatricians. Forty children, primarily with gastrointestinal symptoms, who met criteria for a co-occurring anxiety disorder, were randomly assigned to a cognitive-behavioral treatment addressing pain and anxiety, Treatment of Anxiety and Physical Symptoms (TAPS), or to a waiting list control.

RESULTS

TAPS was found to be an acceptable treatment for this population and was superior to the waiting list condition. Eighty percent of children in TAPS were rated as treatment responders by independent evaluators compared with none of the controls. Overall, self- and parent ratings indicated reductions in children's somatic discomfort and anxiety following intervention. TAPS participants maintained clinical gains 3 months following treatment.

CONCLUSIONS

The study supports the feasibility and preliminary efficacy of a cognitive-behavioral intervention targeting co-occurring physical distress and anxiety in youth presenting for medical treatment. Such an approach has the potential to exert broad impact on children's dysfunction and to minimize exposure to invasive, ineffective, and costly medical procedures and treatments.

When to reconsider the diagnosis of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a highly prevalent disorder characterized by nonspecific symptoms that can mimic other common medical conditions. A careful history and physical examination may reveal clues that suggest a coexisting or alternative diagnosis, such as small intestinal bacterial overgrowth or celiac disease (CD). Testing for bacterial overgrowth has limitations, but emerging data suggest that antibiotics may be of some benefit in patients with IBS with diarrhea and bloating. CD seems to have a higher prevalence in patients with IBS. Some patients with IBS may have symptomatic improvement on gluten-restricted diets, without histologic or serologic evidence of CD.

Irritable bowel syndrome: epidemiology, diagnosis and treatment: an update for health-care practitioners

Irritable bowel syndrome (IBS), a chronic gastrointestinal disorder, affects from 3-20% of the US population, depending on sociocultural and comorbid factors. IBS is characterized by a symptom complex of abdominal pain and abnormal bowel habits that present as diarrhea or constipation, and general physical weakness in the absence of abnormal morphological, histological or inflammatory markers. The main diagnostic Rome III criteria as established by international professional organizations are based on exclusion criteria and the occurrence and rate of symptoms. Because the pathophysiology and causes of IBS are poorly understood, treatment approaches are mainly focused on symptom management to maintain everyday functioning and improve quality of life for persons with IBS. The mainstay of intervention is pharmacological treatment with antispasmodics and antidiarrheals for diarrhea, prokinetics and high-fiber diets for constipation, and supportive therapy with low-dose antidepressants to normalize gastrointestinal motility. Other interventions include lifestyle and dietary changes, psychotherapy, herbal therapies and acupuncture. The purpose of this review is to critically assess benefits and risks of current treatment approaches as well as promising complementary and alternative therapies.

Irritable bowel syndrome is strongly associated with generalized anxiety disorder: a community study

BACKGROUND

No previous study has examined the comorbidity of Irritable Bowel Syndrome (IBS) and Generalized Anxiety Disorder (GAD) in a general population using standardized diagnostic methods.

AIM

To examine the prevalence, comorbidity and risk correlates of IBS and GAD in a general population.

METHODS

A random community-based telephone survey was conducted. The questionnaire covered symptoms of IBS, GAD, core depressive symptoms, help-seeking behaviour and functional impairment on the Sheehan Disability Scale.

RESULTS

A total of 2005 participants completed the interview. The current prevalence of IBS was 5.4% and the 12-month prevalence of GAD was 4%. GAD was five times more common among IBS respondents than non-IBS respondents (OR: 5.84, P < 0.001), whereas IBS was 4.7 times more common among GAD respondents than among non-GAD respondents (OR: 6.32, P < 0.001). Core depressive symptoms (OR: 6.25, P < 0.01) and education level (OR: 5.918, P = 0.021) were risk correlates of GAD among IBS respondents. Comorbid respondents were more impaired than respondents having either disorder alone, but were not more likely to seek professional help than IBS-only respondents.

CONCLUSION

Irritable Bowel Syndrome and GAD comorbidity was common and added to impairment in the community. The strong association between psychiatric morbidity and IBS observed in referral centres was not a consequence of increased help-seeking behaviour.

Role of anxiety in the pathophysiology of irritable bowel syndrome: importance of the amygdala

A common characteristic of irritable bowel syndrome (IBS) is that symptoms, including abdominal pain and abnormal bowel habits, are often triggered or exacerbated during periods of stress and anxiety. However, the impact of anxiety and affective disorders on the gastrointestinal (GI) tract is poorly understood and may in part explain the lack of effective therapeutic approaches to treat IBS. The amygdala is an important structure for regulating anxiety with the central nucleus of the amygdala facilitating the activation of the hypothalamic-pituitary-adrenal axis and the autonomic nervous system in response to stress. Moreover, chronic stress enhances function of the amygdala and promotes neural plasticity throughout the amygdaloid complex. This review outlines the latest findings obtained from human studies and animal models related to the role of the emotional brain in the regulation of enteric function, specifically how increasing the gain of the amygdala to induce anxiety-like behavior using corticosterone or chronic stress increases responsiveness to both visceral and somatic stimuli in rodents. A focus of the review is the relative importance of mineralocorticoid receptor and glucocorticoid receptor-mediated mechanisms within the amygdala in the regulation of anxiety and nociceptive behaviors that are characteristic features of IBS. This review also discusses several outstanding questions important for future research on the role of the amygdala in the generation of abnormal GI function that may lead to potential targets for new therapies to treat functional bowel disorders such as IBS.

A double-blind, randomized, placebo-controlled trial of paroxetine controlled-release in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disease that causes significant impairment in quality of life and accounts for $8 billion per year to the healthcare system and loss of productivity in the workplace.

OBJECTIVE

The authors examined the efficacy and safety of paroxetine controlled-release (paroxetine-CR) in patients with IBS.

METHOD

Seventy-two patients with IBS participated in a 12-week, double-blind, randomized, placebo-controlled study of paroxetine-CR (12.5 mg-50 mg/day). Efficacy was measured by Composite Pain Scores (primary outcome) and the Clinical Global Impression-Improvement (CGI-I) and Severity (CGI-S) ratings.

RESULTS

In intent-to-treat analyses, there were no significant differences between paroxetine-CR (N=36) and placebo (N=36) on reduction in Composite Pain Scores, although the proportion of responders on CGI-I was significantly higher in the paroxetine-CR group. The treatment was well tolerated.

CONCLUSION

The study did not demonstrate a statistically significant benefit for paroxetine-CR over placebo on the primary outcome measure, although there was improvement in secondary outcome measures. Overall, paroxetine-CR seems to have potential benefit in IBS. Studies with adequate samples may clarify the role of paroxetine-CR in IBS.

Acupuncture for irritable bowel syndrome an exploratory randomised controlled trial

BACKGROUND

The evidence on the effectiveness of acupuncture for irritable bowel syndrome (IBS) is inconclusive. However, many patients with IBS are self referring for acupuncture, therefore it is of interest to know whether acupuncture is effective or not. The aim of this study was to establish variability in the primary outcome measure to enable a sample size to be calculated for a full scale trial, and to explore feasibility and design criteria.

METHODS

A pragmatic randomised controlled trial compared 10 sessions of acupuncture plus usual GP care with usual GP care alone. Thirty patients were recruited from four GP databases in Birmingham, UK, and randomised one-to-two to acupuncture or usual care alone. The primary outcome was the IBS Symptom Severity Score (SSS) at three months (maximum score 500). Analysis was by intention-to-treat, and multiple imputation was used for missing data.

RESULTS

From the databases, 189 patients with IBS were identified, of whom 30 were eligible and consented to randomisation. At three months, a statistically and clinically significant difference between groups of 138 points (SD 90) in favour of acupuncture was observed on the IBS SSS (95% CI: 66 to 210; P=0.001) using multiple imputation. For a full scale trial, we estimate that a sample size of 108 patients per arm is required, based on a minimum clinically significant change of 50 points, drawn from a primary care population of 140 000.

CONCLUSIONS

We established the feasibility of a full scale trial, successfully recruiting patients and calculating the sample size required. The results of our pilot analysis suggest that more definitive research into acupuncture for IBS is merited. A pragmatic trial design will not be able to distinguish between acupuncture specific effects and placebo effects; however, it is the design of choice to determine cost effectiveness.

Updates on treatment of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder characterized by abdominal pain and discomfort in association with altered bowel habits. It is estimated to affect 10%-15% of the Western population, and has a large impact on quality of life and (in)direct healthcare costs. IBS is a multifactorial disorder involving dysregulation within the brain-gut axis, and it is frequently associated with gastrointestinal motor and sensory dysfunction, enteric and central nervous system irregularities, neuroimmune dysregulation, and post-infectious inflammation. As with other functional medical disorders, the treatment for IBS can be challenging. Conventional therapy for those with moderate to severe symptoms is largely unsatisfactory, and the development of new and effective drugs is made difficult by the complex pathogenesis, variety of symptoms, and lack of objective clinical findings that are the hallmark of this disorder. Fortunately, research advances over the past several decades have provided insight into potential mechanisms responsible for the pathogenesis of IBS, and have led to the development of several promising pharmaceutical agents. In recent years there has been much publicity over several of these new IBS medications (alosetron and tegaserod) because of their reported association with ischemic colitis and cardiovascular disease. While these agents remain available for use under restricted prescribing programs, this highlights the need for continued development of safe and effective medication for IBS. This article provides a physiologically-based overview of recently developed and frequently employed pharmaceutical agents used to treat IBS, and discusses some non-pharmaceutical options that may be beneficial in this disorder.

Anxiety disorders and comorbid medical illness

OBJECTIVE

To provide an overview of the role of anxiety disorders in medical illness.

METHOD

The Anxiety Disorders Association of America held a multidisciplinary conference from which conference leaders and speakers reviewed presentations and discussions, considered literature on prevalence, comorbidity, etiology and treatment, and made recommendations for research. Irritable bowel syndrome (IBS), asthma, cardiovascular disease (CVD), cancer and chronic pain were reviewed.

RESULTS

A substantial literature supports clinically important associations between psychiatric illness and chronic medical conditions. Most research focuses on depression, finding that depression can adversely affect self-care and increase the risk of incident medical illness, complications and mortality. Anxiety disorders are less well studied, but robust epidemiological and clinical evidence shows that anxiety disorders play an equally important role. Biological theories of the interactions between anxiety and IBS, CVD and chronic pain are presented. Available data suggest that anxiety disorders in medically ill patients should not be ignored and could be considered conjointly with depression when developing strategies for screening and intervention, particularly in primary care.

CONCLUSIONS

Emerging data offer a strong argument for the role of anxiety in medical illness and suggest that anxiety disorders rival depression in terms of risk, comorbidity and outcome. Research programs designed to advance our understanding of the impact of anxiety disorders on medical illness are needed to develop evidence-based approaches to improving patient care.

Psychological distress and GI symptoms are related to severity of bloating in women with irritable bowel syndrome

Bloating is a frequent complaint of women with irritable bowel syndrome (IBS). We compared retrospective and daily diary gastrointestinal and psychological distress symptoms in 183 women ages 18-48 in three IBS subgroups: Minimal-Bloating, Mild-Bloating, Moderate-Severe-Bloating. More women with moderate to severe levels of bloating reported a history of hard stools, straining to have a stool, a history of depressive disorders, and more severe daily symptoms of depression and anxiety as compared to women with minimal or mild bloating symptoms. Appraising the level of symptom severity and psychological distress is vital to the selection of appropriate treatment options.

History of depressive and anxiety disorders and paroxetine response in patients with irritable bowel syndrome: post hoc analysis from a placebo-controlled study

OBJECTIVE

Although irritable bowel syndrome (IBS) is highly comorbid with depressive and anxiety disorders, information on the clinical implications of this comorbidity is limited. We investigated whether a history of depressive and/or anxiety disorders was associated with response to treatment in a double-blind, randomized, placebo-controlled trial of paroxetine controlled release (CR) in IBS.

METHOD

Seventy-two IBS subjects (diagnosed using Rome II criteria) were recruited from August 2003 to November 2005 and randomly assigned to receive flexibly dosed paroxetine CR (dose, 12.5-50 mg/day) or placebo for 12 weeks. The Mini-International Neuropsychiatric Interview (MINI-Plus version) was used to ascertain current (exclusionary) or past diagnoses of depressive and anxiety disorders. Subjective depression, anxiety, and stress were assessed at entry and throughout the trial using the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Perceived Stress Scale (PSS). Severity of IBS symptoms was determined by the Composite Pain Score (CPS), administered via Interactive Voice Response System, and the Clinical Global Impressions scale (CGI). The primary outcome was treatment response defined as ≥ 25% reduction in CPS from randomization to end of treatment. A post hoc analysis (multivariate logistic regression) was done to evaluate whether a history of depressive and/or anxiety disorder was associated with response to medication.

RESULTS

Baseline demographic and clinical characteristics (CPS, BDI, BAI, PSS, CGI scores) were similar between groups (history of depressive/anxiety disorder vs. no history). In multivariate logistic regression analysis, treatment response was not predicted by history of depressive and/or anxiety disorder (OR = 0.58, CI = 0.29 to 1.68, p = .32) or drug status (paroxetine CR vs. placebo) (OR = 1.26, CI = 0.68 to 3.21, p = .19). Drug status was significantly associated with the secondary outcome variable of treatment response as defined by a CGI improvement score of 1 to 2 (OR = 12.14, CI = 2.9 to 48.4, p < .001). Paroxetine CR was safe and well tolerated during the study.

CONCLUSIONS

History of depressive and/or anxiety disorder was not associated with response of IBS symptoms to paroxetine CR. Conclusions are limited due to insufficient statistical power. Further research is needed to clarify the role of selective serotonin reuptake inhibitors in the treatment of IBS and to elucidate the treatment ramifications of comorbid psychiatric disorders.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00610909.

Relationship of functional gastrointestinal disorders and psychiatric disorders: Implications for treatment

This article revisits the links between psychopathology and functional gastrointestinal disorders such as irritable bowel syndrome (IBS), discusses the rational use of antidepressants as well as non-pharmacological approaches to the management of IBS, and suggests guidelines for the treatment of IBS based on an interdisciplinary perspective from the present state of knowledge. Relevant published literature on psychiatric disorders, especially somatization disorder, in the context of IBS, and literature providing direction for management is reviewed, and new directions are provided from findings in the literature. IBS is a heterogeneous syndrome with various potential mechanisms responsible for its clinical presentations. IBS is typically complicated with psychiatric issues, unexplained symptoms, and functional syndromes in other organ systems. Most IBS patients have multiple complaints without demonstrated cause, and that these symptoms can involve systems other than the intestine, e.g. bones and joints (fibromyalgia, temporomandibular joint syndrome), heart (non-cardiac chest pain), vascular (post-menopausal syndrome), and brain (anxiety, depression). Most IBS patients do not have psychiatric illness per se, but a range of psychoform (psychological complaints in the absence of psychiatric disorder) symptoms that accompany their somatoform (physical symptoms in the absence of medical disorder) complaints. It is not correct to label IBS patients as psychiatric patients (except those more difficult patients with true somatization disorder). One mode of treatment is unlikely to be universally effective or to resolve most symptoms. The techniques of psychotherapy or cognitive-behavioral therapy can allow IBS patients to cope more readily with their illness. Specific episodes of depressive or anxiety disorders can be managed as appropriate for those conditions. Medications designed to improve anxiety or depression are not uniformly useful for psychiatric complaints in IBS, because the psychoform symptoms that sound similar to those seen in psychiatric disorders may not have the same significance in patients with IBS.

Changes of psychosocial factors, enteric mucosal mast cells and 5-hydroxytryptamine in irritable bowel syndrome

AIM: To explore the roles of psychosocial factors, enteric mucosal mast cells (MC) and 5-hydroxytryptamine (5-HT) in the pathogenesis of irritable bowel syndrome (IBS).

METHODS: Hamilton anxiety scale (HAMA) and Hamilton depression scale (HAMD) were used to evaluate the psychosocial status of 27 IBS patients and controls. Immunohistochemistry was used to examine the number of mucosal MC in ileocecal junction (ICJ), and the content of mucosal 5-HT in ICJ was detected by high-performance liquid chromatography (HPLC) with an electrochemical detector. The relationship among the scores of HAMA and HAMD, the number of MC and the concentration of 5-HT were analyzed.

RESULTS: The scores of HAMA (18.26 ± 6.23) and HAMD (20.93 ± 6.96) in IBS patients were significantly higher than those in the controls (9.15 ± 4.91, 9.89 ± 5.31) (P < 0.05). The number of mucosal MC and the percentage of degranulated MC in ICJ were significantly higher in patients with constipation predominant IBS (C-IBS) (22.1 ± 6.5/HP, 35.4% ± 7.1%) and diarrhea-predominant IBS (D-IBS) (28.4 ± 7.3/HP, 42.3% ± 10.1%) than those in the controls (15.6 ± 6.9/HP, 24.8% ± 7.2%) (P < 0.05), and they were also significantly higher in D-IBS patients than those in C-IBS patients (P < 0.05). The concentration of ileocecal mucosal 5-HT in C-IBS (2669 ± 920 ng/g) and D-IBS (2628 ± 906 ng/g) patients was markedly higher than that in the controls (1893 ± 984 ng/g) (P < 0.05), and it was not significantly different between D-IBS and C-IBS patients (P > 0.05). The scores of HAMA and HAMD were positively correlated with the number of MC (r = 0.784, 0.711) and the percentage of degranulated MC (r = 0.842, 0.860) in ICJ mucosa of IBS patients (P < 0.01), but not with the concentration of mucosal 5-HT (P > 0.05). The concentration of mucosal 5-HT was not correlated with the number of mucosal MC and the percentage of degranulated MC (P > 0.05).

CONCLUSION: IBS patients show the abnormal psychosocial status, increased number of MC, elevated percentage of degranulated MC and enhanced 5-HT in ICJ. The abnormal psychosocial factors are correlated with the increased number and degranulation of mucosal MC.

Post-traumatic stress disorder and other co-morbidities in a sample population of patients with irritable bowel syndrome

BACKGROUND

High rates of psychiatric co-morbidity have been reported in patients with irritable bowel syndrome (IBS) and high rates of post-traumatic stress disorder (PTSD) have been reported in fibromyalgia, a disorder also associated with IBS. The primary aim of this study was to assess the frequency of PTSD in IBS patients.

METHODS

Sixty-four patients who fulfilled the Rome II diagnostic criteria for IBS were asked to complete questionnaires measuring the prevalence and severity of symptoms of PTSD and psychological distress.

RESULTS

Although 86% of IBS patients reported a traumatic life experience, only 7.8% met the diagnostic criteria for PTSD. High rates of somatization, obsessive-compulsive behavior, interpersonal sensitivity, and anxiety symptoms were seen among the IBS patients.

CONCLUSIONS

The results show a lower than expected prevalence of PTSD among IBS patients, which is similar to that of the general population. Thus, we did not find that PTSD is over-represented in a sample population of IBS patients.

Role of corticotropin-releasing factor pathways in stress-related alterations of colonic motor function and viscerosensibility in female rodents

BACKGROUND

Clinical reports have shown that irritable bowel syndrome (IBS) is comorbid with anxiety/depression and stress-related events, and that the disorder is more prevalent among women than among men. In rodents, colorectal distention (CRD) induces abdominal contractions, and this visceromotor response is used to assess visceral pain. The activation of brain corticotropin-releasing factor (CRF) pathways has a key role in the behavioral and visceral responses to stress.

OBJECTIVE

In this review of experimental studies that delineate the underlying mechanisms of the stress response, we focused on CRF signaling pathways and sex hormones in modulating visceral hypersensitivity induced by CRD in rodents.

METHODS

The findings of our recent research on the development of an experimental model of visceral pain in female rats and the modulation of the hyperalgesic response to CRD by CRF antagonists were integrated with those of the published literature. A MEDLINE search of the years 1981 to 2005 was conducted using the key words stress, CRF, CRH, CRF1 receptor, IBS, CRD, female rat, visceral pain, estrogen, and anxiety.

RESULTS

CRF and other related mammalian peptides (urocortins) interact with the distinct CRF subtype 1 and 2 receptors. Well-documented preclinical studies have established the role of brain CRF1 receptors in mediating stress-related anxiogenic and visceral (stimulation of colonic motor function and sensitization to repeated CRD) responses in male rodents, whereas more limited studies have been performed in female rats. Our recent study indicated that the CRF1 antagonist antalarmin prevents visceral hypersensitivity induced by 2 sets of CRD in female rats. In several models of visceral pain induced by CRD, sex differences and a sensitization action of estrogen were reported. Our preliminary evidence indicated a potentiating interaction between CRF-CRF1 pathways and estrogen in the stimulation of colonic motor responses that may take place within the enteric neurons of the colon, where both CRF1 and estrogen receptors are present.

CONCLUSIONS

The results of this review suggest that overactivity of CRF1 signaling in the brain and the gut may have relevance in understanding the comorbidity of anxiety/depression and IBS in diarrhea-predominant female patients. Targeting these mechanisms with CRF1 antagonists may provide a novel therapeutic strategy.

Corticotropin-releasing hormone receptor 1 antagonist blocks brain-gut activation induced by colonic distention in rats

BACKGROUND & AIMS

The corticotropin-releasing hormone receptor 1 mediates stress-induced changes in colonic motor activity and emotion. We tested the hypothesis that pretreatment with JTC-017, a specific corticotropin-releasing hormone receptor 1 antagonist, blocks colorectal distention-induced hippocampal noradrenaline release and visceral perception in rats. We also investigated whether pretreatment with JTC-017 blocks acute or chronic colorectal distention-induced adrenocorticotropic hormone release, anxiety, and stress-induced changes in colonic motility.

METHODS

Rats were pretreated intrahippocampally with alpha-helical corticotropin-releasing hormone (1.25 microg/kg; vehicle), a nonspecific corticotropin-releasing hormone receptor antagonist, or intraperitoneally with JTC-017 (10 mg/kg). Hippocampal noradrenaline release after microdialysis and the frequency of abdominal contractions were measured in response to acute colorectal distention. Plasma adrenocorticotropic hormone levels, anxiety-related behavior, and stress-induced changes in colonic motility were evaluated after acute or chronic colorectal distention followed by exposure to an elevated plus maze.

RESULTS

Administration of alpha-helical corticotropin-releasing hormone or JTC-017 significantly attenuated hippocampal noradrenaline release and reduced the frequency of abdominal contractions induced by acute distention. In addition, JTC-017 significantly reduced plasma adrenocorticotropic hormone and anxiety after acute distention. After chronic distention, changes in plasma adrenocorticotropic hormone and anxiety were not significant because of habituation. In contrast, a significant increase in fecal pellet output during the elevated plus maze was observed after chronic distention. This increase in fecal pellet output was blocked by pretreatment with JTC-017.

CONCLUSIONS

Our results suggest that JTC-017, a specific corticotropin-releasing hormone receptor 1 antagonist, attenuates hippocampal noradrenaline release, visceral perception, adrenocorticotropic hormone release, and anxiety after acute colorectal distention in rats. In addition, JTC-017 blocks stress-induced changes in colonic motility after chronic colorectal distention in rats.

Cognitive-behavioral treatment of irritable bowel syndrome

There is increasing evidence that supports the view that irritable bowel disorder (IBS) is a disorder of brain-gut function. Cognitive-behavioral therapy (CBT) has received increased attention in light of this recent shift in the conceptualization of IBS. This review has two main aims. The first is to provide a critical review of controlled trials on CBT for IBS. The second is to discuss ways of further developing CBT interventions that are more clinically relevant and meaningful to health care providers and individuals with a diagnosis of IBS. A theme from a CBT intervention will be presented to illustrate how CBT interventions can be incorporated within a larger social context. A review of CBT for IBS lends some limited support for improvement in some IBS symptoms and associated psychosocial distress. This conclusion needs to be expressed with some caution, however, in light of many methodological shortcomings including small sample sizes, inadequate control conditions and failure to identify primary versus secondary outcome measures. In addition, future studies will need to further develop more relevant CBT protocols that more fully integrate the patient's perspective and challenge social cognitions about this stigmatized disorder.

Increased prevalence of functional gastrointestinal disorders in panic disorder: clinical and theoretical implications

BACKGROUND

Functional gastrointestinal disorders (FGID) are a group of disorders characterized by recurrent gastrointestinal distress for which no structural or biochemical cause can be discerned. Irritable bowel syndrome (IBS) is an FGID estimated to affect 10% to 25% of the United States population. IBS occurs in over 40% of individuals with panic disorder, and in patients with IBS, 25% to 30% have panic disorder, which has led to speculation about possible shared pathophysiology between the two. Less is known about the prevalence of other FGID in individuals with panic disorder.

OBJECTIVE

The purpose of this study was to examine the prevalence of IBS and all the other FGID in patients with current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) panic disorder.

INTRODUCTION

We assessed FGIDs in 73 treatment-seeking DSM-IV panic disorder patients via the Diagnostic Interview Questions for Functional Gastrointestinal Disorders and made descriptive comparisons with a large convenience sample from an already-completed United States Household Survey (USHS), which employed the same diagnostic criteria.

RESULTS

The prevalence of IBS and other FGIDs in both men and women with panic disorder were substantially higher than in the USHS respondents. Women with panic disorder had significantly more functional chest pain than men, but there was no gender difference in IBS. With the exception of functional anorectal and biliary disorders, the FGID prevalences were comparatively higher in panic disorder versus the USHS respondents.

DISCUSSION

This survey supports earlier reports of a high prevalence of IBS in individuals with panic disorder and also suggests that the prevalence of several other FGIDs were comparatively high as well. Methodological limitations precluded direct statistical analysis. It may be that commonly overlapping psychiatric and often-painful FGIDs, and extra-intestinal disorders increase the risk for comorbidity in already-affected individuals via shared pathophysiology. One potential model for which there is some evidence for a role in stress, panic disorder, FGIDs and several extra-intestinal functional conditions is dysregulation of corticotropin-releasing factor function.

CONCLUSION

The prevalence of FGIDs in DSM-IV panic disorder was comparatively higher than in USHS respondent community sample, which used similar FGID diagnostic criteria. The cause for the apparent close association of panic disorder with FGID may represent shared pathophysiology. Increased understanding of the mechanism of the overlap may allow for improved treatment of the significant proportion of the population suffering from comorbid psychiatric and functional medical conditions.

Open-label treatment with citalopram in patients with irritable bowel syndrome: a pilot study

BACKGROUND

This open-label pilot study investigated whether the selective serotonin reuptake inhibitor (SSRI) citalopram improves symptoms of irritable bowel syndrome (IBS), a functional gastrointestinal disorder with frequent psychiatric comorbidity.

METHOD

Fifteen patients meeting Rome I criteria for IBS were administered open-label citalopram (20-40 mg/day) for 12 weeks. The study was conducted from October 2000 to August 2001.

RESULTS

Twelve (80%) of the 15 subjects reported a > or = 50% decrease in the presence of abdominal pain, 10 (67%) reported a > or = 50% reduction in the severity of the symptom, and 12 (80%) reported a > or = 50% reduction in the frequency of the symptom. Approximately one half of the patients met criteria for remission (> or = 70% improvement) of abdominal pain.

CONCLUSION

Results of this pilot study suggest that large controlled trials are needed to further evaluate the efficacy of SSRIs such as citalopram for the treatment of IBS.

Psychological treatments for irritable bowel syndrome: a systematic review and meta-analysis

This study conducted a systematic review to assess the quality of existing literature on psychological treatments for irritable bowel syndrome and to quantify the evidence for their efficacy. Three independent reviewers (2 from England, 1 from the United States) coded the quality of 32 studies, 17 of which provided data suitable for meta-analysis. Meta-analysis of efficacy data (50% reduction of symptoms) gave an odds ratio of 12 (95% confidence interval = 5.56-25.96) and a number needed to treat of 2. Psychological treatments are, as a class of interventions, effective in reducing symptoms compared with a pooled group of control conditions. Questions regarding the relative superiority of specific psychological treatments and influence of active versus nonspecific treatment effects remain unanswered.

Citalopram treatment of pediatric recurrent abdominal pain and comorbid internalizing disorders: an exploratory study

OBJECTIVE

To assess the potential efficacy, tolerability, and safety of citalopram in the treatment of functional pediatric recurrent abdominal pain and comorbid internalizing disorders.

METHOD

Twenty-five clinically referred children and adolescents with recurrent abdominal pain aged 7 to 18 years, inclusive, participated in a 12-week, flexible-dose, open-label trial of citalopram. Primary outcome measure was the Clinical Global Impression Scale-Improvement, with responders defined by ratings of 1 (very much improved) or 2 (much improved). Secondary measures included self- and parent reports of abdominal pain, anxiety, depression, other somatic symptoms, and functional impairment. Side effects were assessed using a standardized checklist. Data were analyzed using an intent-to-treat format and the last observation carried forward procedure.

RESULTS

Twenty-one subjects (84%) were classified as responders (Clinical Global Impression Scale-Improvement score < or =2). Citalopram was generally well tolerated. Four subjects withdrew prematurely, one due to reported visual side effects. Ratings of abdominal pain, anxiety, depression, other somatic symptoms, and functional impairment all improved significantly over the course of the study compared with baseline.

CONCLUSIONS

Citalopram is a promising treatment for functional pediatric recurrent abdominal pain and deserves additional study with a randomized, placebo-controlled clinical trial.

Central nervous system involvement in functional gastrointestinal disorders

Although functional gastrointestinal disorders (FGID) are common, their pathophysiology remains incompletely understood. It is generally accepted that dysfunction of the bidirectional pathways between the gastrointestinal tract and the central nervous system (the 'brain-gut axis') at any level can cause FGID symptoms. In this review article, we focus on the role of the central nervous system in the brain-gut axis. First, we describe the functional anatomy of the brain-gut axis. Second, we focus on the results from brain-imaging studies both in healthy volunteers and in FGID patients. These new investigational techniques made identification of brain regions critically involved in processing of visceral afferent information possible. Differences in central nervous system response to visceral stimuli between controls and FGID patients will be highlighted. Third, we will address the issue of high comorbidity with psychiatric disorders. Some hypotheses about common pathophysiological substrates will be discussed.

Intestinal microecology and quality of life in irritable bowel syndrome patients

AIM: It has been noticed that gastroenteritis or dysentery plays a role in pathogenesis of irritable bowel syndrome (IBS), and antibiotics can increase functional abdominal symptoms, both of which may be partly due to intestinal flora disorders. This study was to determine the change of gut flora of IBS, a cluster of abdominal symptoms. Because of the chronic course and frequent occurrence of the disease, IBS patients suffered much from it. So the quality of life (Qol) of IBS patients was also evaluated in this study.

METHODS: Twenty-five Rome II criteria-positive IBS patients were recruited, and 25 age and gender-matched healthy volunteers were accepted as control. The fecal flora, including Lactobacillus, Bifidobacterium, Bacteroides , C. perfringens Enterobacteriacea and Enterococus, were analyzed quantitatively and qualitatively. We also calculated the ratio of Bifidobacterium to Enterobacteriaceae (B/E ratio) in both IBS patients and controls. In both groups, the data were further analyzed based on age difference, and comparisons were made between the younger and elder subgroups. We also evaluated the quality of life (QoL) of IBS patients and the control group using the Chinese version of SF-36 health questionnaire.

RESULTS: In IBS patients, the number of fecal Bifidobacterium was significantly decreased and that of Enterobacteriaceae was significantly increased compared with that in healthy controls (both P < 0.05).The mean microbial colonization resistance (CR) of the bowel in IBS patients was smaller than 1, making a significant difference compared with that in control which was more than 1 (P < 0.01). There was no significant difference in gut flora between two subgroups. While in control, the elder subgroup presented more Enterobacteriacea than the younger one (P < 0.05). Compared with the control group, IBS patients had significantly lower scores on all SF-36 scales, with the exception of physical functioning. However, there was no significant correlation between quality of life and enteric symptoms in IBS patients.

CONCLUSION: There are intestinal flora disorders in IBS patients, which may be involved in triggering the IBS-like symptoms. IBS patients experience significant impairment in QoL, however, the impairment is not caused directly by enteric symptoms.

The interface of psychiatry and irritable bowel syndrome

The interface of psychiatry and irritable bowel syndrome (IBS) is well established, with psychiatric comorbidity approaching 20% to 60%. Anxiety disorders, depressive disorders, and somatoform disorders are the more frequently occurring comorbid conditions. Moreover, psychosocial stressors and history of trauma and abuse play a significant role in the onset and perpetuation of IBS symptoms. The psychiatric management of IBS more effectively uses a collaborative approach between a mental health practitioner and a primary care clinician or gastroenterologist. Psychiatric treatment includes the use of pharmacotherapy with antidepressants or anxiolytics, psychotherapy, and attention to psychosocial stressors. Psychiatric interventions have consistently demonstrated effectiveness in reducing IBS symptoms and improvement of patient functioning.

CRF1 receptor signaling pathways are involved in stress-related alterations of colonic function and viscerosensitivity: implications for irritable bowel syndrome

1. The characterization of corticotropin releasing factor (CRF) and, more recently, the discovery of additional CRF-related ligands, urocortin 1, urocortin 2 and urocortin 3, the cloning of two distinct CRF receptor subtypes, 1 (CRF(1)) and 2 (CRF(2)), and the development of selective CRF receptor antagonists provided new insight to unravel the mechanisms of stress. Activation of brain CRF(1) receptor signaling pathways is implicated in stress-related endocrine response and the development of anxiety-like behaviors. 2. Compelling evidence in rodents showed also that both central and peripheral injection of CRF and urocortin 1 mimic acute stress-induced colonic response (stimulation of motility, transit, defecation, mucus and watery secretion, increased ionic permeability and occurrence of diarrhea) in rodents. Central CRF enhances colorectal distention-induced visceral pain in rats. Peripheral CRF reduced pain threshold to colonic distention and increased colonic motility in humans. 3. Nonselective CRF(1)/CRF(2) antagonists and selective CRF(1) antagonists inhibit exogenous (central or peripheral) CRF- and acute stress-induced activation of colonic myenteric neurons, stimulation of colonic motor function and visceral hyperalgesia while selective CRF(2) antagonists have no effect. None of the CRF antagonists influence basal or postprandial colonic function in nonstressed animals. 4. These findings implicate CRF(1) receptors in stress-related stimulation of colonic function and hypersensitivity to colorectal distention. Targeting CRF(1)-dependent pathways may have potential benefit against stress or anxiety-/depression-related functional bowel disorders.

Comorbidity of irritable bowel syndrome, panic disorder, and agoraphobia in a Japanese representative sample

OBJECTIVES

Irritable bowel syndrome (IBS) is considered to be a transcultural functional bowel disorder with high comorbidity and psychiatric disorders; but well-designed epidemiologic studies have never been performed in Japan. The purpose of this study was to establish the prevalence of IBS, together with the comorbidity rates of panic disorder (PD) and agoraphobia, employing a large-scale survey based on stratified random sampling.

METHODS

A total of 4,000 subjects aged 20-69 years completed a questionnaire and the results were weighted to ensure representativeness of the Japanese general population. The questionnaire covered key symptoms of IBS, PD, and agoraphobia. The prevalence of IBS and its subtypes was calculated by gender. The comorbidity of PD and agoraphobia with IBS was compared with morbidity in non-IBS subjects; and comorbidity in IBS subjects who had consulted medical practitioners regarding their symptoms and in those who had not was also compared.

RESULTS

The prevalence of IBS was 6.1% in total. It was significantly higher in females than in males. Diarrhea-predominant IBS was more prevalent in males and constipation-predominant IBS in females. The morbidity rates of PD and agoraphobia were significantly higher in IBS than in non-IBS subjects. Comorbidity did not differ between female and male IBS subjects, while morbidity was significantly higher in female than in male non-IBS subjects; and comorbidity did not differ between consulter and nonconsulter subjects.

CONCLUSIONS

The prevalence of IBS and its comorbidity with PD and agoraphobia in Japan were demonstrated to be similar to those reported in Western industrialized countries.

Nonpeptide corticotropin-releasing hormone receptor type 1 antagonists and their applications in psychosomatic disorders

Overproduction of corticotropin-releasing hormone (CRH) and stress system abnormalities are seen in psychiatric diseases such as depression, anxiety, eating disorders, and addiction. Investigations of CRH type 1 receptor (CRHR1) nonpeptide antagonists suggest therapeutic potential for treatment of these and other neuropsychiatric diseases. However, overproduction of CRH in the brain and on its periphery and disruption of the hypothalamic-pituitary-adrenal axis are also found in 'somatic' disorders. Some rare forms of Cushing's disease and related pituitary/adrenal disorders are obvious applications for CRHR1 antagonists. In addition, however, these antagonists may also be effective in treating more common somatic diseases. Patients with obesity and metabolic syndrome who often have subtle, but chronic hypothalamic-pituitary-adrenal hyperactivity, which may reflect central dysregulation of CRH and consequently glucocorticoid hypersecretion, could possibly be treated by administration of CRHR1 antagonists. Hormonal, autonomic, and immune aberrations are also present in chronic inflammatory, autoimmune, and allergic diseases, with considerable evidence linking CRH with the observed abnormalities. Furthermore, autonomic dysregulation is a prominent feature of common gastrointestinal disorders, such as irritable bowel syndrome and peptic ulcer disease. Patients with irritable bowel syndrome and other gastrointestinal disorders frequently develop altered pain perception and affective symptoms. CRH acts peripherally to modulate bowel activity both directly through the autonomic system and centrally by processing viscerosensory and visceromotor neural signals. This review presents clinical and preclinical evidence for the role of CRH in the pathophysiology of these disorders and for potential diagnostic and therapeutic applications of CRHR1 antagonists. Recognition of a dysfunctional stress system in these and other diseases will alter the understanding and treatment of 'psychosomatic' disorders.

Prevalence of irritable bowel syndrome among university students: the roles of worry, neuroticism, anxiety sensitivity and visceral anxiety

OBJECTIVE

Relationships between presence of irritable bowel syndrome (IBS) and generalized anxiety disorder (GAD), chronic worry, neuroticism, anxiety sensitivity and anxiety about visceral sensations were examined among university students.

METHODS

College student participants were administered self-report diagnostic measures of IBS and GAD, the Penn State Worry Questionnaire (PSWQ), the Neuroticism subscale of the Eysenck Personality Questionnaire, the Anxiety Sensitivity Index (ASI) and five additional items designed to measure visceral anxiety.

RESULTS

The prevalence of IBS and its associated characteristics among students were similar to previous community survey studies, with the exception of lower symptom severity in the university sample. IBS was associated with a higher frequency of GAD and greater worry, neuroticism, anxiety sensitivity and visceral anxiety. Logistic regression analyses further showed that the measure of anxiety specific to visceral sensations was the strongest predictor of IBS diagnostic status.

CONCLUSIONS

While various aspects of anxiety appear related to IBS, specific anxiety about visceral sensations appears to be the most significant factor. Implications of the associations between anxiety-related variables, particularly anxiety about visceral sensations, are discussed.

Comorbidity of irritable bowel syndrome in psychiatric patients: a review

Irritable bowel syndrome (IBS), a functional gastrointestinal disorder, is present in 10% to 20% of the U.S. adult population. The syndrome is best defined as chronic abdominal discomfort with changes in stool frequency, consistency, and passage, with associated symptoms such as abdominal bloating or presence of mucus in stools. Several studies have shown that up to 70% to 90% of patients with IBS who seek treatment have psychiatric comorbidity, most notably mood and anxiety disorders. Recent studies have shown a high prevalence of IBS in psychiatric patients who seek treatment, with a prevalence of 19% in schizophrenia, 29% in major depression, and 46% in panic disorder among other disorders. Our article reviews the comorbidity of IBS in psychiatric patients and discusses implications for treatment.

Marked suppression of gastric ulcerogenesis and intestinal responses to stress by a novel class of drugs

When exposed to prolonged stress, rats develop gastric ulceration, enhanced colon motility with depletion of its mucin content and signs of physiological and behavioral arousal. In this model, we tested whether antidepressants (fluoxetine and bupropion), anxiolytics (diazepam and buspirone) or the novel nonpeptide corticotropin-releasing hormone (CRH) type-1 receptor (CRH-R1) antagonist, antalarmin, modify these responses. Fluoxetine, bupropion, diazepam and antalarmin all suppressed stress-induced gastric ulceration in male Sprague-Dawley rats exposed to four hours of plain immobilization. Antalarmin produced the most pronounced anti-ulcer effect and additionally suppressed the stress-induced colonic hypermotility, mucin depletion, autonomic hyperarousal and struggling behavior. Intraperitoneal CRH administration reproduced the intestinal but not the gastric responses to stress while vagotomy antagonized the stress-induced gastric ulceration but not the intestinal responses. We conclude that brain CRH-R1 and vagal pathways are essential for gastric ulceration to occur in response to stress and that peripheral CRH-R1 mediates colonic hypermotility and mucin depletion in this model. Nonpeptide CRH-R1 antagonists may therefore be prophylactic against stress ulcer in the critically ill and therapeutic for other pathogenetically related gastrointestinal disorders such as peptic ulcer disease and irritable bowel syndrome.