depression and anxiety and the effectiveness of cognitive behavioural therapy in ibs patients: a randomized controlled trial

backgrounds: anxiety and depression are found to be the major contributors to irritable bowel syndrome (ibs). the present study aimed to measure the effect of a specifically designed cognitive behavioural therapy (cbt) program on the severity of the symptoms and quality of life of patients with chronic ibs, and also define whether anxiety and depression in patients with ibs at baseline affect their response to cbt.   methods: the participants were randomly allocated to conventional treatment only (n=25, control) or cbt plus conventional treatment (n=25, intervention) group. the intervention group attended an eight session group stress management training course conducted by a psychologist in a meeting room at a gastrointestinal clinic at yasuj university of medical sciences. pre- and post-interventions and 3-month follow-up visits were scheduled and conducted by an experienced healthcare worker to measure the primary outcomes and levels of depression and anxiety in the patients. the study was conducted on 2011.   results: the raw group difference (rgd) and standardised mean differences (smd) for the post-treatment scores of the intervention group, when compared with those of the control group, indicated a considerable improvement in the severity of ibs symptoms (rgd=−10.48, smd=−1.23), anxiety (rgd=−9.90, smd=−0.725), d epression ( rgd=−9.57, smd=−0.785) a nd patient’s quality of life (md=−16.81, smd=−0.469). no association (and interaction with cbt) was found between anxiety/depression at baseline and post-treatment or follow-up scores of the outcomes.   conclusion: although cbt improved anxiety, depression, severity of ibs and quality of life of patients with ibs, its effect was independent of the initial level of anxiety and depression of the patients.   trial registration number: irct201102195868n1