Spotlight on mental health and gastrointestinal symptoms

One recent study found a link between depression and diarrhea and constipation, while another found that cognitive behavioral therapy may be an effective treatment for patients with refractory irritable bowel syndrome.

The link between mental health and gastrointestinal (GI) symptoms was the focus of two recent studies, which correlated depression and disordered bowel habits and found that telephone- or web-based cognitive behavioral therapy (CBT) may be an effective treatment for patients with refractory irritable bowel syndrome (IBS).

To evaluate the relationship between mood and bowel habits, researchers in the first study used 2009 to 2010 data from the National Health and Nutrition Examination Survey (NHANES) to identify 491 depressed and 4,669 nondepressed adults who completed the Bowel Health Questionnaire. Eligible patients were older than age 20 years and did not report a history of inflammatory bowel disease or celiac disease. Depression was defined according to the Patient Health Questionnaire 9 in the NHANES depression screener, using the following severity cutoff scores: mild depression (5 to 9), moderate depression (10 to 14), and moderately severe to severe depression (15 or greater). Researchers controlled for many variables, including selective serotonin reuptake inhibitor use, socioeconomic factors, and intake of substances including caffeine, alcohol, fiber, and sugar. Results were published online on April 4 by Clinical Gastroenterology and Hepatology.

In the weighted sample, 24.33% (95% CI, 19.57% to 29.81%) of depressed individuals and 12.54% (95% CI, 11.17% to 14.07%) of nondepressed individuals reported disordered bowel habits (P<0.0001). Compared to those without depression, depressed individuals had a higher prevalence of both chronic diarrhea (15.13% vs. 5.96%; P=0.0001) and chronic constipation (9.20% vs. 6.58%; P=0.003). In multivariable analyses, moderate and severe depression were significantly associated with chronic diarrhea (P=0.002 and P=0.014, respectively), but only mild depression was significantly associated with chronic constipation (P=0.027).

Limitations of the study include the risk of bias in the NHANES database (e.g., recall bias in self-reported data) and the fact that it focused on stool consistency and no other GI symptoms, such as abdominal pain, precluding the ability to identify individuals with IBS, the study authors said.

The authors noted that clinicians treating patients with chronic GI conditions should be prepared to screen for concerns regarding low mood and to refer to appropriate mental health or health psychology services, such as the growing field of psychogastroenterology interventions. “These therapies are typically short-term and problem-focused interventions (such as [CBT] or gut-focused hypnotherapy) that are distinct from traditional psychotherapy treatments for depression or anxiety,” they wrote.

The second study, a three-arm randomized controlled trial, evaluated the effectiveness of two modes of CBT for patients with IBS (telephone-delivered CBT and web-based CBT with minimal therapist support), compared with treatment as usual. Participants were adults with refractory IBS (defined as clinically significant symptoms for 12 or more months despite first-line therapies) recruited from 74 general practices and three gastroenterology centers in London and the South of England between May 2014 and March 2016. The primary outcomes were IBS Symptom Severity Score (IBS-SSS; maximum score, 500) and Work and Social Adjustment Scale (WSAS; maximum score, 40) at 12 months. Results were published online on April 10 by Gut.

A total of 558 patients (mean age, 43 years; 76% women) were randomized to telephone CBT (n=186), web-based CBT (n=185), and treatment as usual (n=187). Overall, 392 (70.3%) patients completed 12 months of follow-up, which was lower than the anticipated follow-up rate of about 80%. At 12 months, IBS-SSS scores were 61.6 points lower in the telephone CBT group (P<0.001) and 35.2 points lower in the web-based CBT group (P=0.002) compared with treatment as usual (IBS-SSS, 205.6). WSAS scores were 3.5 points lower in the telephone CBT group (P<0.001) and 3.0 points lower in the web-based CBT group (P=0.001) compared with treatment as usual (WSAS score, 10.8) at 12 months.

Limitations of the trial include lower-than-expected rates of follow-up and the possibility that trial participants may not be representative of all patients with IBS, the study authors noted. “Currently, clinicians have few options to offer people with refractory IBS, particularly in primary care,” they wrote. “This study shows IBS-specific [telephone-delivered] CBT and [web-based] CBT can provide significant improvement in IBS symptoms, within [a National Health Service (NHS)] setting (NHS therapists delivered the interventions).”