There is probably a similar logic operating in other conditions, both brain and gut......
http://goo.gl/QXoQRxIn the study, higher levels of anxiety and depression were significant predictors of developing IBS or indigestion within 1 year. People who did not have elevated levels of anxiety and depression at the start of the study but had documented IBS or indigestion reported significantly higher levels of anxiety and depression after 1 year.
The researchers calculated that in one-third of individuals, a mood disorder precedes gastrointestinal disorder, but in two-thirds a gastrointestinal disorder precedes the mood disorder.
"We believe these results are really a breakthrough in conceptualizing IBS. The data indicate some patients with IBS have a primary gut disease that may not only explain their gut symptoms but also their psychological distress," said Prof. Nicholas Talley, senior author of the Alimentary Pharmacology & Therapeutics study.