Australian researchers are learning more about how irritable bowel syndrome and anxiety are linked through specific gut-to-brain and brain-to-gut pathways, according to a study published in the July 22 issue of Alimentary Pharmacology and Therapeutics.
“We calculated in one-third of individuals a mood disorder precedes functional gastrointestinal disorder, but in two-thirds an FGID precedes the mood disorder,” researchers stated in the study. “This study provides strong direct evidence that the gut and brain interact bidirectionally in both IBS and functional dyspepsia.”
The study looked at a random sample of subjects from Newcastle, Australia in 2012 and followed up with them a year later. A total of 1900 surveys were completed at follow-up and analyzed by the researchers. They found that higher levels of anxiety and depression at baseline were significant predictors of developing IBS.
Among those who didn’t have elevated levels of anxiety at baseline but had IBS alone, there was a significant amount of anxiety reported at their one-year follow-up. In addition, 6.4% of respondents developed new onset IBS, 7.2% developed functional dyspepsia, and half who had IBS or FD at the beginning of the study reported that they no longer had symptoms.
IBS may first begin with gut symptoms such as diarrhea in people free of distress, “… and only later does new onset anxiety or depression develop, implicating gut disease as the primary driver of the entire symptom complex (a gut-to-brain disease),” Laureate Professor Nicholas J. Talley, one of the study’s researchers, said in a MedicalResearch.com interview. “On the other hand, we speculated there is another quite different subgroup where disease begins with anxiety or depression and only later do new onset gut symptoms develop, and this is likely primarily a central nervous system cause (probably through the stress system), or a brain-to-gut disease.”
“Our novel observations may have profound treatment implications, because if anxiety begins first targeting this brain problem may provide the most benefit, but if gut symptoms begin first directing therapy to the gut may be the more effective approach, a hypothesis now worth testing in clinical trials,” Talley said in the medicalresearch.com interview.
According to the IBSclinic.org website, psychological factors are known to have a long-term effect on the physiological system. “Normal GI function is characterized by a high degree of coordination between the gut and brain,” the website stated. “However, in IBS patients, there is a disruption in this interaction of the brain-gut axis. This often results in abnormal gut motility and visceral hypersensitivity.”
Risk factors for developing psychological distress in IBS can include stress; comorbid psychiatric diagnoses such as anxiety and panic disorder; and emotion-focused rather than problem-focused coping, among others.
The Anxiety and Depression Association of America reports one in five adults have IBS. “The National Digestive Diseases Information Clearinghouse estimates that up to 70% of people with IBS are not receiving treatment,” the ADAA website stated. “Of those who do seek treatment, research has found that 50% to 90% have a psychiatric disorder such as an anxiety disorder or depression.”
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