Pain perception in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by chronic abdominal discomfort or pain in the absence of detectable organic disease. IBS is common and is associated with a significant impairment in health-related quality of life. Enhanced perception of visceral stimuli ("visceral hypersensitivity") appears to be an important pathophysiological mechanism. Early IBS studies using functional brain imaging techniques suggest an alteration in central pain modulation circuits, rather than an increased sensitivity of peripheral visceral pain pathways. The frequent comorbidity with psychiatric disorders suggests the possibility of shared pathophysiological mechanisms and etiologic factors.     

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.     

Brief cognitive-behavioral internet therapy for irritable bowel syndrome

While cognitive-behavioral therapy for IBS is quite effective, the limited availability of competent therapists and lack of access to treatment remain problematic. This paper reports on a small, randomized, controlled trial of a five week internet based cognitive-behavioral intervention for IBS with limited therapist feedback via e-mail. Fifty-four IBS patients were recruited via the internet and randomly assigned to either immediate treatment or a wait-list control group. Thirty-one subjects completed the post-treatment assessment. 77% of treatment completers also completed a 3-month follow-up assessment. Treatment completers experienced statistically and clinically significant declines in IBS symptoms and improvements in quality of life. Those gains were substantially maintained at follow-up. Treatment efficacy was partially mediated by reductions in the tendency to catastrophize the social and occupational implications of symptoms, suggesting that catastrophizing may be an important target for treatment.     

Local-global processing in obsessive-compulsive disorder and comorbid Tourette's syndrome

Neuropsychological and neuroimaging studies implicate attentional difficulties in obsessive-compulsive disorder (OCD), but results are inconsistent due possibly to sample heterogeneity and lack of control of comorbid disorders, such as Tourette's syndrome (TS). Nevertheless, it has been suggested that OCD symptomatology may be a result of over-focused attention at a local level. Therefore, this study aimed to examine the ability of OCD patients (pure and comorbid OCD + TS) to process local and global stimuli. Using a local-global paradigm, participants were required to respond to the directed level (local or global) of various stimuli. Results indicate that pure OCD participants were impaired on the global task, whereas comorbid OCD + TS participants had difficulty processing local information. Results are consistent with previously reported lateralisation anomalies and suggest that OCD negatively affects the ability to process hierarchically presented stimuli.     

Early abuse, psychiatric diagnoses and irritable bowel syndrome

In a population of 71 (57 female, 14 male) IBS patients seeking psychological treatment, we found expected levels of childhood sexual and physical abuse (57.7%) and expected levels of current Axis I psychiatric disorders (54.9%). Moreover, we found those who had been victims of early abuse had higher current Beck Depression Inventory scores. However, contrary to expectations, there were no significant associations between early abuse and current psychiatric disorder in this population, suggesting that those individuals with psychological distress are not exactly the same group with a history of abuse.     

The semantic Simon effect in Tourette's syndrome and obsessive-compulsive disorder

Core symptoms of Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD) may be attributed to an impairment in inhibitory control. Neuropsychological studies have addressed inhibition in both disorders, but findings have been inconsistent. The aim of this study was to examine cognitive inhibition, using a semantic Simon effect paradigm, in patients with TS and OCD. Furthermore, to address comorbidity a group of TS+OCD patients was also examined. Results indicated that patients with TS and OCD were affected by the inhibitory components of the task. TS groups performed similarly to controls on simple and choice RT tasks, but were particularly compromised as increasingly complex inhibitory demands were imposed. OCD patients were slower and committed more errors than controls, especially in the more cognitively demanding conditions, and were particularly disadvantaged by incongruent stimulus-response compatibilities. Findings implicate possible fronto-striatal dysfunction, are consistent with previously reported inhibitory deficits in TS and OCD, and support the theory that comorbid TS+OCD is more closely linked to pure TS than OCD.     

The role of anxiety and depression in the irritable bowel syndrome

Using a reliable and valid structured diagnostic interview scale (ADIS-R), and patients with careful medical characterization, we found significantly more diagnosable psychopathology, particularly anxiety disorders, among treatment seeking patients with irritable bowel syndrome than among comparable age and sex samples of treatment seeking patients with Inflammatory Bowel Disease. Significant differences were also found on the Hamilton Anxiety Rating Scale and Hamilton Rating Scale for Depression between IBS patients and the IBD patients and controls, who did not differ. Comparable levels of psychiatric disorder among parents of probands were found in all three groups. The results are consistent with Latimer's (1983) notion of IBS patients being a subclass of 'neurotics'.     

Prediction of outcome from cognitive-behavioral treatment of irritable bowel syndrome

The presence of a diagnosable Axis I psychiatric disorder predicted significantly (P < 0.001) lower likelihood of significant improvement among 90 irritable bowel syndrome patients given cognitive and behavioral treatments to help the disorder. Other psychological tests, including the MMPI, BDI, STAI, as well as demographic variables, failed to yield significant prediction.     

Behaviorally treated irritable bowel syndrome patients: a four-year follow-up

Nineteen of 27 patients suffering from Irritable Bowel Syndrome (IBS) who had completed a multicomponent treatment involving progressive muscle relaxation, thermal biofeedback, cognitive therapy and IBS education were located and evaluated 4 yr posttreatment. Seventeen of 19 (89.5, or 63% of the total original sample) rated themselves as more than 50% improved. Six of the 12 patients (50%) who submitted symptom monitoring diaries met our criteria for clinical improvement, i.e. achieving at least a 50% reduction in primary IBS symptom scores. The means on all measures at long-term follow-up were lower than those obtained prior to treatment. When follow-up symptom means were compared with pretreatment means, significant (P less than 0.05) reductions were obtained on abdominal pain/tenderness, diarrhea, nausea, and flatulence.     

Selective attention in obsessive-compulsive disorder

Recent information-processing studies have suggested that a selective attention deficit may be involved in the symptomatology of obsessive-compulsive disorder (OCD). In this study, individuals diagnosed with OCD were distinguished from those with panic disorder and from control participants by their relatively poorer performance on a series of psychometric tasks of selective attention. These results are interpreted as supporting the hypothesis of a diminished ability of people with OCD to selectively ignore competing external (sensory) and internal (cognitive) stimuli, especially intrusive thoughts.     

Thought suppression in obsessive-compulsive disorder

Social cognition research has indicated that attempts to suppress thoughts can lead to a paradoxical increase in the frequency of that thought. This phenomenon has been a central component of cognitive-behavioural models of obsessive-compulsive disorder (OCD); however, research has yet to demonstrate deficient thought suppression ability in OCD patients. We examined whether individuals with OCD (OCs) exhibit a deficit in the ability to suppress thoughts. In Experiment 1, attempted thought suppression led to a paradoxical increase in self-reported thoughts for OCs, but not for nonanxious controls (NACs) or anxious controls (ACs). In order to rule out self-report biases, in Experiment 2 we utilized a lexical decision paradigm that measured priming strength of a target word under thought suppression conditions. Results paralleled those of Experiment 1: OCs showed decreased lexical decision latency of the 'suppressed' thought (thought to reflect either increased priming strength or disrupted processing of nonsuppressed thoughts), thus exhibiting a paradoxical effect of thought suppression. This effect was not seen in NACs or ACs. These findings suggest that deficits in cognitive inhibitory processes may underlie the intrusive, repetitive nature of clinical obsessions.     

Action-monitoring dysfunction in obsessive-compulsive disorder

Evidence suggests that a hyperactive frontal-striatal-thalamic-frontal circuit is associated with the symptoms of obsessive-compulsive disorder (OCD), but there is little agreement about the function of the exaggerated activity. We report electrophysiological evidence suggesting that part of this system monitors events and generates error signals when the events conflict with an individual's internal standards or goals. Nine individuals with OCD and 9 age-, sex-, and education-matched control participants performed a speeded reaction time task. The error-related negativity, an event-related brain potential component that reflects action-monitoring processes, was enhanced in the individuals with OCD. The magnitude of this enhancement correlated with symptom severity. Dipole modeling suggested that the locus of the enhancement corresponded to medial frontal regions, possibly the anterior cingulate cortex.     

Two controlled evaluations of multicomponent psychological treatment of irritable bowel syndrome.

We report two controlled comparisons of a previously validated multicomponent (relaxation, thermal biofeedback, and cognitive therapy) treatment for irritable bowel syndrome (IBS) to an ostensible attention-placebo control (pseudo-meditation and EEG alpha suppression biofeedback) and to a symptom-monitoring control. In Study 1 (n = 10 per condition) there were nonsignificant trends for the multicomponent treatment to be superior to the attention-placebo condition. In Study 2 (n = 30 per condition), we found no advantage for the multicomponent treatment over the attention-placebo condition. Subjects in both treatment conditions showed significant reductions in GI symptoms, as measured by daily symptom diaries, and significant reductions in trait anxiety and depression. The GI symptom reductions held up over a 6 month follow-up. Possible explanations for the results are explored.     

Thought dismissability in obsessive-compulsive disorder versus panic disorder

This study sought to better understand the persistence of obsessive-compulsive disorder (OCD) by studying the dismissability of obsessional thoughts in individuals with OCD relative to the dismissability of panic-relevant thoughts in individuals with panic disorder with or without agoraphobia (PD/A). Individuals with a principal diagnosis of OCD (n = 25) or PD/A (n = 25) completed a thought replacement task in which they replaced a primary obsession (target thought for the OCD group) or a primary panic-relevant thought (target thought for the PD/A group), with a neutral thought, signaling when the target thought occurred and when the neutral thought was in mind. The OCD group had more target thoughts and appraised the recurrence of the target thought more negatively. Whereas mood state did not change in the PD/A group, it declined in the OCD group, and this change was predicted by negative appraisal of target thought recurrences, but not amount of time thinking the target thought. These findings suggest that in vivo appraisal of the recurrence of obsessions may be a unique, key mechanism in the persistence of OCD and that the identification and exploration of appraisal of thought recurrences may be an especially important target in its treatment.     

A controlled evaluation of group cognitive therapy in the treatment of irritable bowel syndrome

We randomized, at two sites, 210 patients with Rome II diagnosed irritable bowel syndrome (IBS), of at least moderate severity, to one of three conditions: group-based cognitive therapy (CT; n=120), psychoeducational support groups (n=46) as an active control, or intensive symptom and daily stress monitoring (n=44). One hundred eighty-eight participants completed the initial treatment. Those in symptom monitoring were then crossed over to CT. For an intent to treat analysis on a composite GI symptom measure derived from daily symptom diaries, both CT and the psychoeducational support groups were significantly more improved than those in the intensive symptom monitoring condition, but the CT and psychoeducational support group did not differ. Among treatment completers on the same composite measure of GI symptoms, again, both CT and psychoeducational support groups were statistically superior to symptom monitoring but did not differ on the symptom composite, or on any other measure. On individual IBS symptoms, both CT and psychoeducational support were statistically superior to symptom monitoring on reductions in abdominal pain and tenderness and for flatulence. Patient global ratings at the end of treatment showed the two active conditions statistically superior to symptom monitoring on change in Bowel Regularity, with CT superior to symptom monitoring on reduction in overall pain and in improvement in sense of well-being. Three-month follow-up data on 175 patients revealed maintenance of significant improvement or continued significant improvement on all IBS symptoms, including the McGill Pain Questionnaire. Group CT and psychoeducational support groups continued not to differ on any measure. We thus conclude that group CT is not superior to an attention placebo control condition.