Comorbidity of posttraumatic stress disorder and irritable bowel syndrome

Genetic associations and potential mediators between psychiatric disorders and irritable bowel syndrome: a Mendelian randomization study with mediation analysis

Objective

Potential causal associations between psychiatric disorders and irritable bowel syndrome have been demonstrated in observational studies; however, these studies are susceptible to underlying confounding and reverse causation biases. We aimed to assess the causal effects of psychiatric disorders on irritable bowel syndrome (IBS) and the potential mediators from a genetic perspective by conducting a Mendelian randomization (MR) study with mediation analysis.

Method

Genetic instruments associated with psychiatric disorders, potential mediators, and IBS were obtained from large-scale genome-wide association studies (GWAS). Three MR methods - the inverse-variance weighted (IVW) method, MR-Egger method, and weighted median method, were used to investigate causal association estimates. Heterogeneity among different genetic instrumental variables (IVs) was assessed using Q tests. Additionally, the MR-PRESSO and MR-Pleiotropy methods were used to verify horizontal pleiotropy and detect outliers that might bias the results, which were removed from further analysis. Consequently, we used MR mediation analysis to investigate potential mediators in the causal associations between psychiatric disorders and IBS.

Results

MR provided evidence of the causal effects of genetically predicted broad depression, major depressive disorder (MDD), anxiety disorder, post-traumatic stress disorder (PTSD), and schizophrenia on IBS. The results of MR mediation analysis demonstrated that the reduction in acetate levels mediated 12.6% of the effects of broad depression on IBS; insomnia mediated 16.00%, 16.20%, and 27.14% of the effects of broad depression, MDD, and PTSD on IBS, respectively; and the increase in blood β-hydroxybutyrate levels mediated 50.76% of the effects of schizophrenia on IBS.

Conclusion

Our study confirmed the brain-gut axis involvement and potential modulators in the pathophysiology of psychiatric disorder-induced IBS from a genetic perspective, and suggests potential therapeutic targets for the disrupted brain-gut axis.

Irritable Bowel Syndrome and the Gut Microbiome: A Comprehensive Review

Irritable Bowel Syndrome (IBS) is a functional disorder of the gastrointestinal tract characterized by abdominal pain and altered bowel habits. It has a prevalence of 10 to 25% in the United States and has a high disease burden, as evidenced by reduced quality of life, decreased work productivity and increased healthcare utilization and costs. IBS has been associated with several intra-intestinal and extra-intestinal conditions, including psychiatric comorbidities. Although the pathophysiology of IBS has not been fully elucidated, it involves dysregulation of communication between the brain and gut (brain–gut axis) which is associated with alterations in intestinal motility, gut permeability, visceral hypersensitivity and gut microbiota composition. The purpose of this article is to review the role the gut microbiota plays in the pathophysiology of IBS, understand factors that affect the gut microbiome and explore the microbiome as a target of treatment.

Prevalence of Gastrointestinal Symptoms and Irritable Bowel Syndrome Among Individuals With Symptomatic Posttraumatic Stress Disorder

GOALS

Our aim was to describe the prevalence of irritable bowel syndrome (IBS) and other gastrointestinal symptoms in a sample of veterans with posttraumatic stress disorder (PTSD) and to examine the relationship between gastrointestinal symptoms, PTSD severity, depression severity, and number of prior traumatic events reported.

BACKGROUND

IBS and PTSD can co-occur; yet, little research has focused on describing the gastrointestinal symptoms and prevalence of IBS among veterans with PTSD.

MATERIALS AND METHODS

We examined baseline data from a randomized clinical trial of behavioral interventions for veterans with PTSD. Veterans completed questionnaires assessing gastrointestinal symptoms (Gastrointestinal Patient-Reported Outcome Measures Information Systems; PROMIS) and lifetime traumatic events. Multivariable regression analyses were performed to examine associations between gastrointestinal symptoms and the number of prior traumas reported PTSD severity, and depression symptom severity.

RESULTS

One hundred eighty-four veterans with a diagnosis of PTSD were included. Twenty-five percent met the Rome III criteria for IBS. Veterans reported gastrointestinal symptoms including abdominal/belly pain (36%), diarrhea (21%), constipation (18%), and bloating/gas (17%). In multivariable analyses, greater PTSD severity was associated with worse constipation ( P =0.008), diarrhea ( P =0.005), and gas/bloating ( P =0.001) when controlling for age and sex. Higher levels of depressive symptoms severity were associated with greater abdominal/belly pain ( P =0.04).

CONCLUSIONS

Among a sample of veterans with PTSD, rates of IBS and abdominal/belly pain are greater than general US population reference values. Although levels of constipation and bloating/gas are lower than general US population reference values, increased severity of PTSD was associated with increased gastrointestinal symptoms.

Diagnostic accuracy of the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) within a civilian primary care sample

OBJECTIVE

This study aims to evaluate the diagnostic accuracy of the Primary Care Posttraumatic Stress Disorder (PTSD) Screen for Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) (PC-PTSD-5) as a screening tool for the identification of PTSD among a civilian sample receiving behavioral health treatment within a primary care setting. Validation within a civilian sample will increase the generalizability of the PC-PTSD-5 as a brief screening measure to identify PTSD within primary care practices.

METHOD

The present study is a retrospective review of data (N = 198) collected as part of a patient registry for an integrated behavioral health consultation service within a primary care clinic. The PC-PTSD-5 was administered as part of a standardized set of brief screening measures and a standard clinical interview. Diagnostic validation was accomplished via a consensus model between a board-certified family medicine physician and a licensed psychologist along with medical/psychology trainees.

RESULTS

Fifty-two participants (26.26%) out of 198 who completed the PC-PTSD-5 were diagnosed with PTSD. The PC-PTSD-5 demonstrated excellent diagnostic accuracy (area under the curve = 0.933, 95% confidence interval [CI]: 0.901-0.965). A cutoff score of 4 maximized sensitivity (sensitivity% = 100) while maintaining acceptable specificity (specificity% = 85.2). This score also maximized efficiency (κ[0.5] = 0.77, SE = 0.05, 95% CI: 0.67-0.86) and maintained a good (≥0.60) quality index for specificity (κ[0] = 0.61).

CONCLUSION

The PC-PTSD-5 maintained strong diagnostic accuracy within a civilian primary care sample.

Prevalence and Impact of Post-traumatic Stress Disorder in Gastrointestinal Conditions: A Systematic Review

Psychological distress is often observed in patients with gastrointestinal illness. To date, there has been limited research conducted to assess the prevalence and impact of post-traumatic stress disorder (PTSD) in gastrointestinal cohorts. The aim of this systematic review is to review the evidence for the prevalence of PTSD in gastrointestinal cohorts versus comparator groups (healthy controls and chronic illness groups), predictive factors associated with the development and management of PTSD and the impact on patient outcomes. Adult studies were identified through systematic searches of eight databases (MEDLINE, Embase, Emcare, PsycINFO, Ovid Nursing, CINAHL, Informit Health Collection, and Cochrane Library) in February 2020. The overall pooled prevalence rate of PTSD in GI cohorts was 36%; however, the prevalence rate in non-veteran-specific gastrointestinal cohorts of 18% across all GI classification groups is likely to be the more representative rate. The non-gastrointestinal chronic illness cohort PTSD prevalence rate was 11%. Predictors identified in the development of post-traumatic stress in gastrointestinal cohorts include: female gender, poor social support, life adversity, subjective pain, and dietary choices. Post-traumatic stress was found to exacerbate gastrointestinal symptoms in a Crohn's Disease sample, whereby disease exacerbation was four times in those who met the criteria for probable PTSD. Post-traumatic stress symptoms affect around one in five individuals (non-veteran status) with a gastrointestinal condition. Further research is needed to understand the psychological and biological mechanisms by which PTSD increases the risk of developing and exacerbating gastrointestinal symptoms.

Do somatic symptoms relate to PTSD and gender after earthquake exposure? A cross-sectional study on young adult survivors in Italy

OBJECTIVE

Increasing evidence confirms a strict relationship between mental disorders and physical health. Particularly, stressful life events and post-traumatic stress disorder (PTSD) have been closely correlated with various physical disorders and somatic symptoms, such as chronic pain, gastrointestinal disorders, and headaches. The aim of this study was to investigate the emergence of somatic symptoms in a sample of young adult survivors 21 months after exposure to the L'Aquila 2009 earthquake, with particular attention to PTSD and gender impact.

METHODS

Four hundred and fifty high-school senior students (253 male and 197 female) exposed to the 2009 L'Aquila earthquake, 21 months earlier, were enrolled and evaluated by the Trauma and Loss Spectrum Self-Report (TALS-SR), for symptomatological PTSD, and the Mood Spectrum Self-Report-Lifetime Version (MOODS-SR) "rhythmicity and vegetative functions" domain, for somatic symptoms.

RESULTS

Significantly higher rates of endorsement of the MOODS-SR somatic symptoms emerged in survivors with PTSD compared to those without. Females reported higher rates of endorsement of at least one MOODS-SR somatic symptom compared to males; however, a Decision Tree model and a two-way analysis of variance model confirmed a significant effect of PTSD only. A multivariate logistical regression showed a significant association between the presence of at least one MOOD-SR somatic symptom and re-experiencing and maladaptive coping TALS-SR domains.

CONCLUSION

This study corroborates a relevant impact of symptomatological PTSD, across both the genders, on somatic symptoms occurring in young adults after months from exposure to a massive earthquake.

Cumulative Effect of Psychological Alterations on Gastrointestinal Symptom Severity in Irritable Bowel Syndrome

INTRODUCTION

Psychological alterations are common and considered important for symptom generation in irritable bowel syndrome (IBS). However, the possible cumulative effect of having multiple psychological alterations on gastrointestinal (GI) symptom severity in IBS is largely unknown.

METHODS

Patients with IBS (Rome IV) completed validated questionnaires assessing GI symptoms (Gastrointestinal Symptom Rating Scale, IBS version and IBS Severity Scoring System), personality traits (Big Five), posttraumatic stress and psychological alterations, anxiety (Generalized Anxiety Disorder 7-item scale and State-Trait Anxiety Inventory), depression (Patient Health Questionnaire, 9-item version), fatigue (Multidimensional Fatigue Inventory), pain catastrophizing, somatization (Patient Health Questionnaire, 12-item version), stress (Perceived Stress Scale), and GI-specific anxiety (Visceral Sensitivity Index). Of the 18 possible psychological factors, those with significant associations with GI symptom severity, corrected for multiple comparisons, were identified. The associations between increasing number of psychological alterations (validated cutoff values or uppermost tertile) and the severity of GI symptoms were analyzed with linear trend analyses.

RESULTS

In total, 106 patients with IBS (Rome IV criteria) were included (72 [68%] women, median age of 35 [interquartile range: 26-45] years). Psychological alterations were common and overlap among these factors were frequently seen. Five psychological factors (physical fatigue, GI-specific anxiety, perceived stress, pain catastrophizing, and trait anxiety) demonstrated significant, noncollinear associations with GI symptom severity. With increasing number of these psychological alterations, a gradual increase was seen in the overall severity of GI symptoms (Gastrointestinal Symptom Rating Scale, IBS version: partial η = 0.268, P < 0.001; IBS Severity Scoring System: partial η = 0.219, P < 0.001, both large effect sizes).

DISCUSSION

Distinct associations were seen between the severity of GI symptoms and individual, as well as an increasing number of psychological alterations. This highlights the importance of understanding different psychological alterations for the disease burden in IBS (visual abstract, Supplementary Digital Content 1, http://links.lww.com/AJG/B756).

Stress and the brain-gut axis in functional and chronic-inflammatory gastrointestinal diseases: A transdisciplinary challenge

The broad role of stress in the brain-gut axis is widely acknowledged, with implications for multiple prevalent health conditions that are characterized by chronic gastrointestinal symptoms. These include the functional gastrointestinal disorders (FGID), such as irritable bowel syndrome and functional dyspepsia, as well as inflammatory bowel diseases (IBD) like ulcerative colitis and Crohn's disease. Although the afferent and efferent pathways linking the gut and the brain are modulated by stress, the fields of neurogastroenterology and psychoneuroendocrinology (PNE)/ psychoneuroimmunology (PNI) remain only loosely connected. We aim to contribute to bringing these fields closer together by drawing attention to a fascinating, evolving research area, targeting an audience with a strong interest in the role of stress in health and disease. To this end, this review introduces the concept of the brain-gut axis and its major pathways, and provides a brief introduction to epidemiological and clinical aspects of FGIDs and IBD. From an interdisciplinary PNE/PNI perspective, we then detail current knowledge regarding the role of chronic and acute stress in the pathophysiology of FGID and IBD. We provide an overview of evidence regarding non-pharmacological treatment approaches that target central or peripheral stress mechanisms, and conclude with future directions, particularly those arising from recent advances in the neurosciences and discoveries surrounding the gut microbiota.

Initial Assessment of Post-traumatic Stress in a US Cohort of Inflammatory Bowel Disease Patients

BACKGROUND

Post-traumatic stress (PTS), or the psycho-physiological response to a traumatic or life-threatening event, is implicated in medical patient outcomes. Emerging evidence suggests a complex relationship between PTS, the brain-gut axis, the gut microbiome, and immune function. Inflammatory bowel disease (IBD) may be susceptible to PTS and its subsequent impacts. To date, no study has evaluated PTS in IBD in the United States.

METHODS

Adult patients with IBD were recruited from an outpatient gastroenterology practice, via social media, and via a research recruitment website. Patients with irritable bowel syndrome (IBS) were recruited as a comparison group. Participants completed demographic and disease information, surgical and hospitalization history, and the PTSD Checklist-Civilian Version (PCL-C). Statistical analyses evaluated rates of PTS in IBD and IBS, including differences between groups for PTS severity. Regression analyses determined potential predictors of PTS.

RESULTS

One hundred eighty-eight participants (131 IBD, 57 IBS) completed the study. Thirty-two percent of IBD and 26% of IBS patients met the criteria for significant PTS symptoms based on PCL-C cutoffs. Inflammatory bowel disease patients are more likely to attribute PTS to their disease than IBS patients. Crohn's disease (CD) patients appear to be the most likely to experience PTS, including those being hospitalized or undergoing ileostomy surgery. Symptom severity is the greatest predictor of PTS for ulcerative colitis and IBS.

CONCLUSIONS

Although PTS is relevant in both IBS and IBD, IBD patients are seemingly more susceptible to PTS due their disease experiences, especially CD patients. The nature of PTS symptoms may contribute to IBD disease processes, most notably through sleep disturbance and ANS arousal. Clinicians should assess for PTS in IBD patients as standard of care, especially after a hospitalization or surgery.

Systematic review with meta-analysis: The association between post-traumatic stress disorder and irritable bowel syndrome

BACKGROUND AND AIM

Post-traumatic stress disorder (PTSD) is a psychiatric condition characterized by symptoms of hyperarousal and hypervigilance. Increasing research on the "gut-brain" axis (bidirectional signaling between the gut and the brain) has drawn links between PTSD and irritable bowel syndrome (IBS), an exceedingly common yet incompletely understood gastrointestinal condition. This meta-analysis thus aimed to examine the body of evidence and extent of association of PTSD with IBS.

METHODS

Using the keywords [early abuse OR childhood abuse OR violence OR trauma OR PTSD] AND [irritable bowel syndrome or IBS], a preliminary search on the PubMed, Medline, Embase, ScienceDirect, PsychINFO, Web of Science, and Google Scholar databases yielded 11,257 papers published in English between January 1, 1988, and May 1, 2018. Of these, only eight studies were included in the final meta-analysis.

RESULTS

The eight studies (four cross-sectional and four cohort) contained a total of 648,375 subjects. Most studies were from the USA and conducted on army veterans. The funnel plot revealed a roughly symmetrical distribution of studies, and Egger test was not significant for publication bias (P = 0.583). Random-effects meta-analysis found PTSD to be a significant risk factor for IBS (pooled odds ratio 2.80, 95% confidence interval: 2.06 to 3.54, P < 0.001).

CONCLUSIONS

Overall, PTSD is associated with an increased likelihood of IBS. This is the first meta-analysis to specifically examine the association between PTSD and IBS, and it provides insights into the probable (patho)physiology and management of IBS, supporting a holistic consideration of the psychosocial aspects of IBS and further research into effective multi-modal therapeutics.

Physical comorbidities of post-traumatic stress disorder in Australian Vietnam War veterans

OBJECTIVE

To determine whether the prevalence of physical comorbidities in Australian Vietnam War veterans with post-traumatic stress disorder (PTSD) is higher than in trauma-exposed veterans without PTSD.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional analysis of the health status (based on self-reported and objective clinical assessments) of 298 Australian Vietnam War veterans enrolled by the Gallipoli Medical Research Institute (Brisbane) during February 2014 - July 2015, of whom 108 were confirmed as having had PTSD and 106 served as trauma-exposed control participants.Main outcomes and measures: Diagnostic psychiatric interview and psychological assessments determined PTSD status, trauma exposure, and comorbid psychological symptoms. Demographic data, and medical and sleep history were collected; comprehensive clinical examination, electrocardiography, spirometry, liver transient elastography, and selected pathology assessments and diagnostic imaging were performed. Outcomes associated with PTSD were identified; regression analysis excluded the effects of potentially confounding demographic and risk factors and comorbid symptoms of depression and anxiety.

RESULTS

The mean total number of comorbidities was higher among those with PTSD (17.7; SD, 6.1) than in trauma-exposed controls (14.1; SD, 5.2; P < 0.001). For 24 of 171 assessed clinical outcomes, morbidity was greater in the PTSD group, including for conditions of the gastrointestinal, hepatic, cardiovascular, and respiratory systems, sleep disorders, and laboratory pathology measures. In regression analyses including demographic factors, PTSD remained positively associated with 17 adverse outcomes; after adjusting for the severity of depressive symptoms, it remained significantly associated with ten.

CONCLUSION

PTSD in Australian Vietnam veterans is associated with comorbidities in several organ systems, independent of trauma exposure. A comprehensive approach to the health care of veterans with PTSD is needed.

Post-traumatic Stress Disorder After Sexual Abuse in Adolescent Girls

The sexual assault of girls and women in this country is estimated at approximately 20%. The development of post-traumatic stress disorder (PTSD) after sexual abuse and assault is one of the potential lingering aftereffects. In this article we describe PTSD after sexual abuse and its effect on presenting complaints, such as sexually transmitted infections, contraception, and chronic pain, for the pediatric and adolescent gynecology (PAG) clinician. Treatment approaches, including the use of antidepressants and anxiolytics, as well as evidenced-based psychotherapies, are highlighted. In addition, this article will assist the PAG clinician in identifying trauma-related concerns during clinic visits and will cover specific screening tools to aid in identification of PTSD. A better understanding of PTSD after sexual abuse will allow PAG providers to deliver better care to their patients.

Early life stress elicits visceral hyperalgesia and functional reorganization of pain circuits in adult rats

Early life stress (ELS) is a risk factor for developing functional gastrointestinal disorders, and has been proposed to be related to a central amplification of sensory input and resultant visceral hyperalgesia. We sought to characterize ELS-related changes in functional brain responses during acute noxious visceral stimulation. Neonatal rats (males/females) were exposed to limited bedding (ELS) or standard bedding (controls) on postnatal days 2–9. Age 10–11 weeks, animals were implanted with venous cannulas and transmitters for abdominal electromyography (EMG). Cerebral blood flow (rCBF) was mapped during colorectal distension (CRD) using [¹⁴C]-iodoantipyrine autoradiography, and analyzed in three-dimensionally reconstructed brains by statistical parametric mapping and functional connectivity. EMG responses to CRD were increased after ELS, with no evidence of a sex difference. ELS rats compared to controls showed a greater significant positive correlation of EMG with amygdalar rCBF. Factorial analysis revealed a significant main effect of ‘ELS’ on functional activation of nodes within the pain pathway (somatosensory, insular, cingulate and prefrontal cortices, locus coeruleus/lateral parabrachial n. [LC/LPB], periaqueductal gray, sensory thalamus), as well as in the amygdala, hippocampus and hypothalamus. In addition, ELS resulted in an increase in the number of significant functional connections (i.e. degree centrality) between regions within the pain circuit, including the amygdala, LC/LPB, insula, anterior ventral cingulate, posterior cingulate (retrosplenium), and stria terminalis, with decreases noted in the sensory thalamus and the hippocampus. Sex differences in rCBF were less broadly expressed, with significant differences noted at the level of the cortex, amygdala, dorsal hippocampus, raphe, sensory thalamus, and caudate-putamen. ELS showed a sexually dimorphic effect (‘Sex x ELS’ interaction) at the LC/LPB complex, globus pallidus, hypothalamus, raphe, septum, caudate-putamen and cerebellum. Our results suggest that ELS alters functional activation of the thalamo-cortico-amydala pathway, as well as the emotional-arousal network (amygdala, locus coeruleus), with evidence that ELS may additionally show sexually dimorphic effects on brain function.

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Early life stress (ELS) elicits visceral hyperalgesia in adult offspring.

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ELS alters functional activation of the thalamo-cortico-amydala pathway.

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ELS shows a sexually dimorphic effects on brain function.

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Functional imaging-based endpoints promise improved animal-to-human translation.

Stress-induced visceral pain: toward animal models of irritable-bowel syndrome and associated comorbidities

Visceral pain is a global term used to describe pain originating from the internal organs, which is distinct from somatic pain. It is a hallmark of functional gastrointestinal disorders such as irritable-bowel syndrome (IBS). Currently, the treatment strategies targeting visceral pain are unsatisfactory, with development of novel therapeutics hindered by a lack of detailed knowledge of the underlying mechanisms. Stress has long been implicated in the pathophysiology of visceral pain in both preclinical and clinical studies. Here, we discuss the complex etiology of visceral pain reviewing our current understanding in the context of the role of stress, gender, gut microbiota alterations, and immune functioning. Furthermore, we review the role of glutamate, GABA, and epigenetic mechanisms as possible therapeutic strategies for the treatment of visceral pain for which there is an unmet medical need. Moreover, we discuss the most widely described rodent models used to model visceral pain in the preclinical setting. The theory behind, and application of, animal models is key for both the understanding of underlying mechanisms and design of future therapeutic interventions. Taken together, it is apparent that stress-induced visceral pain and its psychiatric comorbidities, as typified by IBS, has a multifaceted etiology. Moreover, treatment strategies still lag far behind when compared to other pain modalities. The development of novel, effective, and specific therapeutics for the treatment of visceral pain has never been more pertinent.

The Relationship Between Irritable Bowel Syndrome and Panic Disorder: A Case Study

Evidence suggests that cognitive behaviour therapy is the treatment of choice for both irritable bowel syndrome (IBS) and panic disorder (PD). The present study examines the treatment issues relating to a woman diagnosed with both IBS and PD (with agoraphobia), where therapy for PD was disrupted by IBS symptoms. Group therapy was then initiated for IBS, and this was associated with a large decrease in general anxiety and depression, and an increase in confidence concerning management of the pain caused by the IBS. This finding is discussed with respect to its possible implications for the treatment of people suffering both IBS and PD.

The relationship between irritable bowel syndrome and psychiatric disorders: from molecular changes to clinical manifestations

Irritable bowel syndrome (IBS) is a functional syndrome characterized by chronic abdominal pain accompanied by altered bowel habits. Although generally considered a functional disorder, there is now substantial evidence that IBS is associated with a poor quality of life and significant negative impact on work and social domains. Neuroimaging studies documented changes in the prefrontal cortex, ventro-lateral and posterior parietal cortex and thalami, and implicate alteration of brain circuits involved in attention, emotion and pain modulation. Emerging data reveals the interaction between psychiatric disorders including generalized anxiety disorder, panic disorder, major depressive disorder, bipolar disorder, and schizophrenia and IBS, which suggests that this association should not be ignored when developing strategies for screening and treatment. Psychological, social and genetic factors appear to be important in the development of IBS symptomatology through several mechanisms: alteration of HPA axis modulation, enhanced perception of visceral stimuli or psychological vulnerability. Elucidating the molecular mechanisms of IBS with or without psychiatric comorbidities is crucial for elucidating the pathophysiology and for the identification of new therapeutical targets in IBS.

Irritable bowel syndrome: Relations with functional, mental, and somatoform disorders

This review describes the conceptual and clinical relations between irritable bowel syndrome (IBS), other functional, somatoform, and mental disorders, and points to appropriate future conceptualizations. IBS is considered to be a functional somatic syndrome (FSS) with a considerable symptom overlap with other FSSs like chronic fatigue syndrome or fibromyalgia syndrome. IBS patients show an increased prevalence of psychiatric symptoms and disorders, especially depression and anxiety. IBS is largely congruent with the concepts of somatoform and somatic symptom disorders. Roughly 50% of IBS patients complain of gastrointestinal symptoms only and have no psychiatric comorbidity. IBS concepts, treatment approaches, as well as health care structures should acknowledge its variability and multidimensionality by: (1) awareness of additional extraintestinal and psychobehavioral symptoms in patients with IBS; (2) general and collaborative care rather than specialist and separated care; and (3) implementation of “interface disorders” to abandon the dualistic classification of purely organic or purely mental disorders.

Psychosocial characteristics and pain burden of patients with suspected sphincter of Oddi dysfunction in the EPISOD multicenter trial

OBJECTIVES

Patients with several painful functional gastrointestinal disorders (FGIDs) are reported to have a high prevalence of psychosocial disturbance. These aspects have not been studied extensively in patients with suspected Sphincter of Oddi dysfunction (SOD).

METHODS

A total of 214 patients with post-cholecystectomy pain and suspected SOD were enrolled in seven US centers in a multicenter-randomized trial (Evaluating Predictors and Interventions in Sphincter of Oddi Dysfunction). Baseline assessments included pain descriptors and burden, structured psychosocial assessments of anxiety/depression, coping, trauma, and health-related quality of life. Patients with high levels of depression, suicidal ideation, or psychosis were excluded.

RESULTS

The study population (92% female, mean age 38) reported anxiety (9%), depression (8%), past sexual trauma (18%), and physical abuse (10%). Of the total screened population (n=1460), 3.9% of the patients were excluded because of the presence of defined severe psychological problems. The mean medical outcomes study short-form-36 (SF-36) physical and mental composite scores were 38.70 (s.d.=7.89) and 48.74 (s.d.=9.60), respectively. Most subjects reported symptoms of other FGIDs. There were no correlations between the extent of the pain burden in the 3 months before enrollment and the baseline anxiety scores or victimization history. However, those with greater pain burden were significantly more depressed. There were no meaningful differences in the psychosocial parameters in subjects with or without irritable bowel, and those who had cholecystectomy for stones or functional gallbladder disease. Those declining randomization were comparable to those randomized.

CONCLUSIONS

Psychosocial comorbidity in SOD is high. However, it does not appear to differ significantly from that reported in surveys of age- and gender-matched general populations, and may be lower than reported with other FGIDs.

Association of mental health problems with gastrointestinal disorders in Iraq and Afghanistan veterans

BACKGROUND

Gastrointestinal disorders (GIDs) represent a large public health burden, affecting an estimated 60-70 million Americans annually. Our goal was to examine the relationship between GID and the most common mental health disorders in a national group of newly returning veterans. We also evaluated gender differences in the association of mental health disorders and GID.

METHODS

We utilized a retrospective, longitudinal cohort analysis of veterans' health records. Participants were 603,221 Iraq and Afghanistan veterans who were new users of VA healthcare from October 7, 2001 (start of the war in Afghanistan) to December 31, 2010.

RESULTS

The prevalence of GID in newly returning veterans was nearly 20%, and veterans with a mental health disorder were at least twice as likely to have a GID as those without mental health disorders. For women, the increased risk of all GIDs was greatest among those with depression. Among men, the increased risk of irritable bowel syndrome (IBS) was greatest among those with posttraumatic stress disorder. IBS was the GID most strongly associated with mental health conditions among both genders.

CONCLUSIONS

The large proportion of newly returning veterans with GIDs and comorbid mental health diagnoses is concerning. Successful detection and treatment of GIDs associated with mental health disorders will require integrated efforts from primary care and mental health.

Impaired emotional learning and involvement of the corticotropin-releasing factor signaling system in patients with irritable bowel syndrome

BACKGROUND & AIMS

Alterations in central corticotropin-releasing factor signaling pathways have been implicated in the pathophysiology of anxiety disorders and irritable bowel syndrome (IBS). We aimed to characterize the effects of the corticotropin-releasing factor receptor 1 (CRF-R1) antagonist, GW876008, on brain and skin conductance responses during acquisition and extinction of conditioned fear to the threat of abdominal pain in subjects with IBS and healthy individuals (controls).

METHODS

We performed a single-center, randomized, double-blind, 3-period crossover study of 11 women with IBS (35.50 ± 12.48 years old) and 15 healthy women (controls) given a single oral dose (20 mg or 200 mg) of the CRF-R1 antagonist or placebo. Blood-oxygen level-dependent responses were analyzed using functional magnetic resonance imaging in a tertiary care setting.

RESULTS

Controls had greater skin conductance responses during acquisition than extinction, validating the fear-conditioning paradigm. In contrast, during extinction, women with IBS had greater skin conductance responses than controls-an effect normalized by administration of a CRF-R1 antagonist. Although the antagonist significantly reduced activity in the thalamus in patients with IBS and controls during acquisition, the drug produced greater suppression of blood-oxygen level-dependent activity in a wide range of brain regions in IBS patients during extinction, including the medial prefrontal cortex, pons, hippocampus, and anterior insula.

CONCLUSIONS

Although CRF signaling via CRF-R1 is involved in fear acquisition and extinction learning related to expected abdominal pain in patients with IBS and controls, this system appears to be up-regulated in patients with IBS. This up-regulation might contribute to the previously reported abnormal brain responses to expected abdominal pain.

Irritable bowel syndrome in the UK military after deployment to Iraq: what are the risk factors?

PURPOSE

Diarrhoea and vomiting (D & V) was common in military personnel during deployment to the initial phases of the Iraq war. D & V is an established risk factor for irritable bowel syndrome (IBS). This study examined the prevalence of IBS in a military sample with a history of deployment to Iraq and the association between D & V and common mental disorder (CMD) with IBS.

METHODS

The study used data from a two-phase cohort study of military/personnel. The sample was restricted to individuals who had been deployed to Iraq before phase 1 of the study and who had completed the self-report D & V question. A measure of probable IBS was derived at both phases of the study based on self-reported symptoms in the previous month. CMD was assessed by the General Health Questionnaire (GHQ-12).

RESULTS

Fifty-nine percent of the sample reported a D & V event and 6.6 % met the criteria for probable IBS at phase 1. Reporting D & V, thinking one might be killed on deployment, poor physical health and CMD were associated with probable IBS at phase 1. CMD at phase 1 was strongly associated with chronic symptoms of IBS.

CONCLUSIONS

There was a high prevalence of D & V during deployment to the early stages of the Iraq war, yet the prevalence of probable IBS on return from deployment was relatively low. D & V was strongly associated with IBS after deployment, and CMD was a risk factor for chronic symptoms of IBS.

The physical health consequences of PTSD and PTSD symptoms: a meta-analytic review

The present meta-analysis systematically examined associations between physical health and posttraumatic stress disorder (PTSD)/PTSD symptoms (PTSS), as well as moderators of this relationship. Literature searches yielded 62 studies examining the impact of PTSD/PTSS on physical health-related quality of life (HR-QOL), general health symptoms, general medical conditions, musculoskeletal pain, cardio-respiratory (CR) symptoms, and gastrointestinal (GI) health. Sample-specific and methodological moderators were also examined. Results revealed significantly greater general health symptoms, general medical conditions, and poorer HR-QOL for PTSD and high PTSS individuals. PTSD/PTSS was also associated with greater frequency and severity of pain, CR, and GI complaints. Results of moderation analyses were mixed. However, consistent relationships emerged regarding PTSD assessment method, such that effect sizes were largest for self-reported PTSD/PTSS and all but one health outcome. Results highlight the need for prospective longitudinal examination of physical health shortly following trauma, and suggest variables to consider in the design of such studies.

Altered neuro-endocrine-immune pathways in the irritable bowel syndrome: the top-down and the bottom-up model

The interaction between the brain and the gut as a pathological mechanism of functional gastrointestinal disorders has been recently recognized in the pathophysiology of the irritable bowel syndrome. Communication between central nervous system and enteric nervous system is two-directional: the brain can influence the function of the enteric nervous system and the gut can influence the brain via vagal and sympathetic afferents. In patients with irritable bowel syndrome, symptoms may be caused by alterations either primarily in the central nervous system (top-down model), or in the gut (bottom-up model), or in a combination of both. The brain-gut axis may be stimulated by various stressors either directed to the central nervous system (exteroreceptive stress) or to the gut (interoceptive stress). Particularly, clinical evidence suggest that in complex and multifactorial diseases such as irritable bowel syndrome, psychological disorders represent significant factors in the pathogenesis and course of the syndrome. Neuroimaging techniques have shown functional differences between central process in healthy subjects and patients with irritable bowel syndrome. Moreover, a high prevalence of psychological/psychiatric disorders have been reported in IBS patients compared to controls. Several data also suggest an alteration of neuro-endocrine and autonomic output to the periphery in these patients. This review will examine and discuss the complex interplay of neuro-endocrine-immune pathways, closely associated with neuropsychiatric disorders.

Stress and visceral pain: from animal models to clinical therapies

Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain.

PTSD treatment of African American adults in primary care: the gap between current practice and evidence-based treatment guidelines

BACKGROUND

Posttraumatic stress disorder (PTSD) is a common, potentially disabling, underdiagnosed, and under-treated illness. Primary care physicians assume a critical role in the diagnosis, treatment, and referral of African Americans with PTSD since mental health access is limited for this population. This study is an examination of PTSD treatment of African Americans in the primary care setting. Actual treatment provision is contrasted with existing evidence-based PTSD treatment guidelines.

METHOD

Researchers screened 738 consenting, mostly African American, adults in 4 academically affiliated primary care offices for both trauma exposure and mental health symptoms, including PTSD.

RESULTS

Employing criteria from the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) (DSM-IV), investigators diagnosed 91 of the participants with current PTSD using the Structured Clinical Interview for DSM and the clinician-administered of PTSD Scale for DSM-IV. Treatment statistics include: 69.2% (n=63) had never received treatment from a mental health provider: 18.6% (n=17) were currently seeing a mental health practitioner; nearly half (47.9%, n=24) of a subsample had never discussed traumatic event exposure or mental health symptoms with their primary care doctor; 32% (n=29) were prescribed psychotropic medication and only 18.6% (n=17) were participating in any form of psychotherapy. Concurrent psychiatric disorders were found in 46.2% (n = 42) of the participants with PTSD.

CONCLUSION

Most African American adult primary care patients with PTSD were either undiagnosed or undertreated in this inner-city setting. These results demonstrate a clear need to improve screening and treatment services. Both individual (provider and patient) and system-based changes will be required to meet the demonstrated clinical need.

Physical health problems after single trauma exposure: when stress takes root in the body

Research has established that chronic stress, including traumatic events, leads to adverse health outcomes. The literature has primarily used two approaches: examining the effect of acute stress in a laboratory setting and examining the link between chronic stress and negative health outcomes. However, the potential health impact of a single or acute traumatic event is less clear. The goal of this literature review is to extend the literature linking both chronic trauma exposure and posttraumatic stress disorder to adverse health outcomes by examining current literature suggesting that a single trauma may also have negative consequences for physical health. The authors review studies on health, including cardiovascular, immune, gastrointestinal, neurohormonal, and musculoskeletal outcomes; describe potential pathways through which single, acute trauma exposure could adversely affect health; and consider research and clinical implications.

Stress-related alterations of visceral sensation: animal models for irritable bowel syndrome study

Stressors of different psychological, physical or immune origin play a critical role in the pathophysiology of irritable bowel syndrome participating in symptoms onset, clinical presentation as well as treatment outcome. Experimental stress models applying a variety of acute and chronic exteroceptive or interoceptive stressors have been developed to target different periods throughout the lifespan of animals to assess the vulnerability, the trigger and perpetuating factors determining stress influence on visceral sensitivity and interactions within the brain-gut axis. Recent evidence points towards adequate construct and face validity of experimental models developed with respect to animals' age, sex, strain differences and specific methodological aspects such as non-invasive monitoring of visceromotor response to colorectal distension as being essential in successful identification and evaluation of novel therapeutic targets aimed at reducing stress-related alterations in visceral sensitivity. Underlying mechanisms of stress-induced modulation of visceral pain involve a combination of peripheral, spinal and supraspinal sensitization based on the nature of the stressors and dysregulation of descending pathways that modulate nociceptive transmission or stress-related analgesic response.

Stress and visceral pain: from animal models to clinical therapies

Epidemiological studies have implicated stress (psychosocial and physical) as a trigger of first onset or exacerbation of irritable bowel syndrome (IBS) symptoms of which visceral pain is an integrant landmark. A number of experimental acute or chronic exteroceptive or interoceptive stressors induce visceral hyperalgesia in rodents although recent evidence also points to stress-related visceral analgesia as established in the somatic pain field. Underlying mechanisms of stress-related visceral hypersensitivity may involve a combination of sensitization of primary afferents, central sensitization in response to input from the viscera and dysregulation of descending pathways that modulate spinal nociceptive transmission or analgesic response. Biochemical coding of stress involves the recruitment of corticotropin releasing factor (CRF) signaling pathways. Experimental studies established that activation of brain and peripheral CRF receptor subtype 1 plays a primary role in the development of stress-related delayed visceral hyperalgesia while subtype 2 activation induces analgesic response. In line with stress pathways playing a role in IBS, non-pharmacologic and pharmacologic treatment modalities aimed at reducing stress perception using a broad range of evidence-based mind-body interventions and centrally-targeted medications to reduce anxiety impact on brain patterns activated by visceral stimuli and dampen visceral pain.

Evidence of overlapping genetic diathesis of panic attacks and gastrointestinal disorders in a sample of male twin pairs

We explored the comorbidity between panic attacks (PA), whose symptoms can include gastrointestinal discomfort, and gastrointestinal disorders (GD). Structural equation modeling was used to analyze data from 1,874 MZ and 1,498 DZ male-male twin pairs from the Vietnam Era Twin Registry. PA and GD were associated (relative risk for GD = 2). The percentage of liability due to genetic factors was estimated to be 37% for PA and 31% for GD. There was significant correlation between the genetic risk factors for PA and GD (estimated r = .55, 95% CI of 34% to 82%) and no evidence of correlation between the environmental causes of PA and GD. Therefore, PA and GD comorbidity can be explained by overlapping genetic factors and not overlapping environmental factors. Although these data cannot identify a biological pathway for such a shared liability, it suggests the presence of GD may be informative for genetic studies of panic.

The role of experimental models in developing new treatments for irritable bowel syndrome

Irritable bowel syndrome (IBS) is characterized by chronic, recurrent abdominal pain and altered bowel habits and is currently defined by symptom criteria and the absence of detectable organic disease. The underlying pathophysiology remains incompletely understood. Despite considerable efforts by the scientific community and the pharmaceutical industry to develop novel pharmacological treatments aimed at chronic visceral pain, the traditional approach to identifying and evaluating novel drugs for this target have largely failed to translate into effective IBS treatments. However, several novel drugs aimed at normalizing bowel movements have produced clinical effects, not only on the primary target, but also on pain and discomfort. While some of the commonly used experimental animal models for the pain dimension of IBS have some face and construct validity, the predictive validity of most of the models is either unknown, or has been disappointing. A reverse translational approach is proposed, which is based on identification and characterization of brain endophenotypes in patients, followed by translation of these endophenotypes for pharmacological studies in rodent models.

The Patient Health Questionnaire 12 Somatic Symptom scale as a predictor of symptom severity and consulting behaviour in patients with irritable bowel syndrome and symptomatic diverticular disease

BACKGROUND

Anxiety, depression and nongastrointestinal symptoms are often prominent in irritable bowel syndrome (IBS), but their relative value in patient management has not been quantitatively assessed. We modified the Patient Health Questionnaire 15 (PHQ-15) by excluding three gastrointestinal items to create the PHQ-12 Somatic Symptom (PHQ-12 SS) scale.

AIMS

To compare the value of the PHQ-12 SS scale with the Hospital Anxiety and Depression (HAD) scale in predicting symptoms and patient behaviour in IBS and diverticular disease.

METHODS

We compared 151 healthy volunteers (HV), 319 IBS patients and 296 patients with diverticular disease (DD), 113 asymptomatic [ASYMPDD] and 173 symptomatic DD (SYMPDD).

RESULTS

Patient Health Questionnaire 12 SS scores for IBS and SYMPDD were significantly higher than HV. Receiver-operator curves showed a PHQ-12 SS >6, gave a sensitivity for IBS of 66.4% with a specificity of 94.7% and a positive likelihood ratio (PLR) = 13.2, significantly better than that associated with an HAD anxiety score >7, PLR = 3.0 and depression score >7 PLR = 6.5. PHQ-12 SS correlated strongly with IBS severity scale and GP visits in both IBS and DD.

CONCLUSION

The PHQ-12 SS scale is a useful clinical tool which correlates with patient behaviour in both IBS and symptomatic DD.

Posttraumatic oxytocin dysregulation: is it a link among posttraumatic self disorders, posttraumatic stress disorder, and pelvic visceral dysregulation conditions in women?

This article explicates a theory that oxytocin, a sexually dimorphic neurotransmitter and paracrine hormone, is a plausible mechanism linking early relational trauma with posttraumatic self disorders (e.g., dissociation, somatization, and interpersonal sensitivity), posttraumatic stress disorder, and pelvic visceral dysregulation disorders (e.g., irritable bowel syndrome, chronic pelvic pain, interstitial cystitis, and hyperemesis gravidarum). This posttraumatic oxytocin dysregulation disorders theory is consistent with the historical and contemporary literature. It integrates attention to psychological and physical comorbidities and could account for the increased incidence of these disorders among females. Specific propositions are explored in data from studies of traumatic stress and women's health.

Effect of sexual and physical abuse on symptom experiences in women with irritable bowel syndrome

BACKGROUND

Irritable Bowel Syndrome (IBS) is a common chronic functional bowel disorder characterized by alterations in bowel patterns and abdominal pain. One factor that is conjectured to contribute to the onset of IBS is sexual and/or physical abuse in childhood or as an adult. This conjecture is supported by the increased prevalence of abuse experiences in persons with IBS when compared to healthy controls or those with organically-defined gastrointestinal (GI) disorders.

OBJECTIVES

The purposes of the present study were to (a) compare the history of sexual and physical abuse in a sample of women with IBS to a sample of women without IBS and (b) to compare women with IBS who had sexual and physical abusive experiences to those who had not on GI symptoms, psychological distress, healthcare-seeking behavior, and physiological measures.

METHODS

Data were collected from two samples of women (ages 18-40 years) with IBS and controls were recruited through community advertisements and letters from a health maintenance organization. Participants completed questionnaires (i.e., Sexual and Physical Abuse, Bowel Disease Questionnaire, Symptom Checklist-90-R) during an in-person interview and completed a symptom diary each night across one menstrual cycle. Cortisol and catecholamine levels were determined in morning urine samples on 6 days across the menstrual cycle.

RESULTS

More women in the IBS group reported unwanted sexual contact during childhood relative to control women. Within the IBS group, minimal differences were found between those who had experienced abuse and those who had not. Women with IBS who had experienced abuse reported greater impact of GI symptoms on activity.

CONCLUSIONS

The prevalence of a history of childhood sexual abuse experiences is elevated among women with IBS. However, within women with IBS, those with a history of abuse do not appear to be different from those with no history of abuse on GI symptoms, psychological symptoms, or physiological arousal indicators.

Does cognitive-behavioral therapy for PTSD improve perceived health and sleep impairment?

There is a paucity of empirical study about the effects of evidence-based psychotherapy for posttraumatic stress disorder (PTSD) on concurrent health concerns including sleep impairment. This study compares the differential effects of cognitive processing therapy (CPT) and prolonged exposure (PE) on health-related concerns and sleep impairment within a PTSD sample of female, adult rape survivors (N = 108). Results showed that participants in both treatments reported lower health-related concerns over treatment and follow-up, but there were relatively more improvements in the CPT condition. Examination of sleep quality indicated significant improvement in both CPT and PE across treatment and follow-up and no significant differences between treatments. These results are discussed with regard to the different mechanisms thought to underlie the treatments and future innovations in PTSD treatment.

Frequency and severity of the symptoms of irritable bowel syndrome across the anxiety disorders and depression

High rates of irritable bowel syndrome (IBS) symptoms have been reported in individuals diagnosed with anxiety and depressive disorders. However, most studies have investigated these relations in a single disorder, rather than a heterogeneous group of patients, thereby not allowing for comparisons across anxiety disorders and depression, or for considering the effects of comorbidity. Thus, the present study investigated the symptoms of IBS in a diverse group of patients (N=357) by administering questionnaires and a diagnostic interview. A high frequency of IBS symptoms was found in patients with panic disorder, generalized anxiety disorder, and major depressive disorder. However, the frequency of IBS symptoms in patients with social anxiety disorder, specific phobia, and obsessive-compulsive disorder was comparable to rates found in community samples. In addition, anxiety sensitivity and illness attitudes and intrusiveness were predictive of elevated IBS symptomatology. Together, these findings emphasize the role physiological symptoms of anxiety and worry in the co-occurrence of the anxiety disorders and IBS.

Irritable bowel syndrome and dyspepsia among women veterans: prevalence and association with psychological distress

BACKGROUND

The burden of functional GI disorders and their associations with psychological distress in women veterans is unclear.

AIM

To examine 1-year prevalence of irritable bowel syndrome (IBS) and dyspepsia symptoms and their associations with anxiety, depression and post-traumatic stress disorder (PTSD) among women veterans receiving primary care at a Veteran Affairs Medical Center Women's Clinic.

METHODS

Irritable bowel syndrome, dyspepsia and psychological distress were assessed using the validated self-administered Bowel Disorder Questionnaire, the Beck Depression and Anxiety Inventories, as well as the Mississippi Scale for Combat-Related Post-Traumatic Stress Disorder Questionnaire.

RESULTS

We enrolled 248 women (84% participation rate). Ninety-three (38%) reported IBS and 51 (21%) dyspepsia symptoms. Women with IBS and dyspepsia reported higher mean scores of anxiety (IBS: 24 vs. 12, P < 0.0005 and dyspepsia: 26 vs. 12, P < 0.0005), depression (IBS: 22 vs. 11, P = 0.0005 and dyspepsia: 23 vs. 11, P < 0.0005) and PTSD (IBS: 87 vs. 69, P < 0.001 and dyspepsia: 86 vs. 69, P < 0.0005). Age- and ethnicity-adjusted logistic regression analyses showed a 3- to 46-fold increase in odds of IBS and dyspepsia among women with anxiety, depression or PTSD.

CONCLUSION

Women veterans have high prevalence of IBS and dyspepsia symptoms, both of which are highly associated with presence of depression, anxiety and PTSD.

Tryptophan catabolism in females with irritable bowel syndrome: relationship to interferon-gamma, severity of symptoms and psychiatric co-morbidity

Irritable bowel syndrome (IBS) has been linked with abnormal serotonin functioning and immune activation. Tryptophan forms the substrate for serotonin biosynthesis, but it can alternatively be catabolized to kynurenine (Kyn) by the enzyme indoleamine 2,3-dioxygenase (IDO), the main inducer of which is interferon-gamma. The primary aim of this study was to test the hypothesis that IBS is associated with increased tryptophan (Trp) catabolism along the Kyn pathway due to increased IFN-gamma levels. Plasma Kyn, Trp and IFN-gamma levels were measured in 41 female IBS subjects and 33 controls. Indoleamine 2,3-dioxygenase activity was assessed using the Kyn to Trp ratio. Psychiatric co-morbidity was assessed using the Patient Health Questionnaire, and severity of IBS assessed using self-report ordinal scales. Irritable bowel syndrome subjects had increased Kyn concentrations compared with controls (P = 0.039) and there was a trend for Kyn:Trp to be increased in the IBS group (P = 0.09). There was a positive correlation between IBS severity and Kyn:Trp (r = 0.57, P < 0.001). Those with severe IBS symptoms had increased Kyn:Trp (P < 0.005) compared to those with less severe symptoms and controls, and were over twice as likely to have depression or anxiety compared to those with less severe IBS (RR = 2.2, 95% CI 1.2-3.9). No difference in IFN-gamma levels was observed between groups; however, IFN-gamma was positively correlated with Kyn:Trp in IBS (r = 0.58, P = 0.005) but not controls (r = 0.12, P = 0.5). Females with IBS have abnormal Trp catabolism. The Kyn:Trp is related to symptom severity, and those with severe IBS symptoms have increased shunting of Trp along the Kyn pathway which contributes to the abnormal serotonergic functioning in this syndrome.

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.

Service use data analysis of pre-pregnancy psychiatric and somatic diagnoses in women with hyperemesis gravidarum

INTRODUCTION

The purpose of this study was to redress weaknesses in past studies of a psychogenic etiology for hyperemesis gravidarum (HG) by (1) estimating from a known population what proportion of HG cases also have psychiatric diagnoses, (2) determining if psychiatric disorder preceded HG, and (3) re-considering whether non-pregnancy somatic conditions also precede HG.

METHODS

We analyzed insurance data for all 11,016 members who gave birth to singletons in 2000-2004, 208 of whom had HG.

RESULTS

Prevalence of HG was 1.8% overall, 3.8% with one psychiatric diagnosis, 5.8% with >1 psychiatric diagnosis. One in 10 HG cases had pre-pregnancy depression, anxiety, or substance abuse diagnoses. One in five HG cases had either a psychiatric or a somatic condition (e.g., chronic pelvic pain, dysmenorrhea) diagnosis prior to pregnancy. Pre-pregnancy psychiatric diagnosis doubled the adjusted odds of HG. Combined psychiatric and somatic diagnoses quadrupled the adjusted odds of HG.

DISCUSSION

Vomiting is a non-specific sign that may have multiple etiologies. For 10-20% of HG sufferers, vomiting may be a physical comorbidity of a psychiatric condition occurring in the context of pregnancy. Psychobiological research with HG cases with past or current psychiatric diagnoses is needed to consider plausible mechanisms.

PTSD and stress sensitisation: a tale of brain and body Part 1: human studies

Post-traumatic stress disorder (PTSD) is a chronic, debilitating psychiatric disorder that can follow exposure to extreme stressful experiences. It is characterised by hyperarousal and increased startle responses, re-experiencing of the traumatic event, withdrawal or avoidance behaviour and emotional numbing. The focus of this review is on aspects that have received less attention. PTSD develops only in a substantial minority of people exposed to traumatic stress, and possible individual traits that increase vulnerability are discussed. An overview is given of the wide variety of physiological disturbances that accompany PTSD and may contribute to disability, including neuroendocrine, cardiovascular, gastrointestinal and immune function and pain sensitivity. Brain imaging and pharmacological studies have generated some insight into the circuitry that may be involved in the generation of PTSD symptoms. Major limitations of human studies so far are the issue of causality and our lack of understanding of the underlying molecular substrates in the brain, which are easier to address in relevant animal models and will be discussed in a companion paper.

Protease-activated receptors: potential therapeutic targets in irritable bowel syndrome?

Protease-activated receptors (PARs) are a family of four G-protein-coupled receptors (PAR-1 to PAR-4) activated by the proteolytic cleavage of their N-terminal extracellular domain. This activation first involves the recognition of the extracellular domain by proteases, such as thrombin, but also trypsin or tryptase which are particularly abundant in the gastrointestinal tract, both under physiological circumstances and in several digestive diseases. Activation of PARs, particularly of PAR-1 and -2, modulates intestinal functions, such as gastrointestinal motility, visceral nociception, mucosal inflammatory response, and epithelial functions (intestinal secretion and permeability). As these physiological properties have been shown to be altered in various extents and combinations in different clinical presentations of irritable bowel syndrome, PARs appear as putative targets for future therapeutic intervention in these patients.

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.