Cognitive factors affect treatment response to medical and psychological treatments in functional bowel disorders

For clinical trials in functional bowel disorders (FBD), the definition of a responder, one who meets the predefined criteria for a clinical response, is needed. Factors that determine clinical response aside from treatment itself are unknown. The aim of this study was to determine what baseline and post-treatment factors affect treatment response.

Females (n=397) with FBD entering a 12-week, four-arm, randomized NIH treatment trial (desipramine (DES), CBT, pill placebo, and education) were studied at baseline and after treatment. Demographic, clinical, psychosocial, and physiological variables were considered in the analysis. A responder was defined as a patient obtaining a score>3.5 on an averaged eight-item, five-point satisfaction-with-treatment questionnaire. Baseline and post-treatment logistic regressions were performed for each treatment condition to predict the responder outcome variable.

Similar cognitive features predisposed participants to treatment response across the treatment conditions: sense of control over the condition, positive relationship with therapist or study coordinator, confidence in treatment, improvement in maladaptive cognitions, and quality of life during treatment. Demographic and clinical variables studied were not predictive. Some treatment-specific effects predicting responder status were noted, including a reduction in stool frequency with DES treatment and lack of abuse history in the placebo group.

For medication, psychological, and placebo treatment in FBD, satisfaction with treatment depends on cognitive factors of confidence in treatments, perceived control over illness and symptoms, and reduction in negative cognitions related to symptom experience. Addressing these issues among patients with FBD may enhance treatment response to a variety of treatments.