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

BACKGROUND: It is well established that people with irritable bowel syndrome (IBS) have higher levels of anxiety and depression compared with controls. However, the role of these as risk factors is less clearly established. The aims of this systematic review were to investigate: (1) whether anxiety and/or depression predict IBS onset; (2) the size of the relative risk (RR) of anxiety versus depression in IBS onset. Subgroup analyses explored if methodological factors affected the overall findings. METHOD: Prospective cohort or case-control studies were included if they: (1) focused on the development of IBS in population-based or gastroenteritis cohorts; (2) explored the effects of anxiety and/or depression at baseline as predictors of IBS onset at a future point. In all, 11 studies were included of which eight recruited participants with a gastrointestinal infection. Meta-analyses were conducted. RESULTS: The risk of developing IBS was double for anxiety cases at baseline compared with those who were not [RR 2.38, 95% confidence interval (CI) 1.58-3.60]. Similar results were found for depression (RR 2.06, 95% CI 1.44-2.96). Anxiety and depression seemed to play a stronger role in IBS onset in individuals with a gastrointestinal infection although this could be attributed to other differences in methodology, such as use of diagnostic interviews rather than self-report. CONCLUSIONS: The findings suggest that self-reported anxiety and depression provide a twofold risk for IBS onset. There is less support for the role of anxiety or depressive disorder diagnosed using clinical interview. These findings may have implications for the development of interventions focused on IBS prevention and treatment.

Establishing how psychological therapies work: the importance of mediation analysis.

This editorial reviews the literature regarding psychological studies that are designed to address the question of not just whether, psychological interventions effect change, but how. The practicalities and implications of assessing mechanisms of treatments are considered with examples from the fields of Cognitive Behavioural Therapy (CBT) and Mindfulness. The potential for elucidating theoretical mechanisms, developing new theoretical models and modifying treatment approaches are described. In addition an overview of different types of statistical methods available to researchers for assessing mediation is given. Structural Equation Modelling (SEM) is a recommended approach. The review concludes with a summary of optimum study conditions adopted by researchers for establishing mediating effects.

Distress improves after mindfulness training for progressive MS: A pilot randomised trial.

BACKGROUND: Mindfulness-based interventions have been shown to effectively reduce anxiety, depression and pain in patients with chronic physical illnesses. OBJECTIVES: We assessed the potential effectiveness and cost-effectiveness of a specially adapted Skype distant-delivered mindfulness intervention, designed to reduce distress for people affected by primary and secondary progressive MS. METHODS: Forty participants were randomly assigned to the eight-week intervention (n = 19) or a waiting-list control group (n = 21). Participants completed standardised questionnaires to measure mood, impact of MS and symptom severity, quality of life and service costs at baseline, post-intervention and three-month follow-up. RESULTS: Distress scores were lower in the intervention group compared with the control group at post-intervention and follow-up (p < 0.05), effect size -0.67 post-intervention and -0.97 at follow-up. Mean scores for pain, fatigue, anxiety, depression and impact of MS were reduced for the mindfulness group compared with control group at post-therapy and follow-up; effect sizes ranged from -0.27 to -0.99 post-intervention and -0.29 to -1.12 at follow-up. There were no differences in quality-adjusted life years, but an 87.4% probability that the intervention saves on service costs and improves outcome. CONCLUSIONS: A mindfulness intervention delivered through Skype video conferences appears accessible, feasible and potentially effective and cost-effective for people with progressive MS.