April 17, 2012 (Arlington, Virginia) — Children with functional abdominal pain (FAP) are up to 5 times more likely to have a comorbid anxiety disorder by 21 years of age than healthy children, new research shows.
In addition, 2 studies presented here at the here at the Anxiety Disorders Association of America 32nd Annual Conference suggest that treating anxiety in adults reduces both gastrointestinal and psychiatric symptoms.
Taken together, the studies show that the early diagnosis and treatment of pediatric anxiety can have a significant impact on the adult brain–gut connection.
"It's a bidirectional relationship. If you have anxiety and depression, you're more likely to have FAP; if you have FAP, you're more likely to have depression," said John Campo, MD, a pediatric psychiatrist who moderated the session.
Dr. Campo, who is professor and chair of the Department of Psychiatry at the Ohio State University Medical Center and chief of behavioral health services at Nationwide Children's Hospital in Columbus, has just completed a study showing that children with anxiety and depression have higher rates of FAP (51.5% vs 8.8%; P = 0.0002), migraine (57.6% vs 23.5%; P = 0.0062), and constipation (21.2% vs 8.8%; P = 0.183) than healthy control subjects.
His previous research showed that 80% of pediatric FAP patients have current anxiety, 43% have current depressive disorder, and 29% have current major depressive disorder.
Dr. Campo's work shows that in children with both FAP and anxiety, anxiety tends to come first (mean age of onset, 6.25 years), followed by FAB (mean age of onset, 9.17 years).
New work by Lynn Walker, PhD, from the Vanderbilt University School of Medicine in Nashville, Tennessee, has shown that children 8 to 15 years of age whose abdominal pain persists to age 21 are 5 times more likely to have an anxiety disorder in adulthood, and that those with pain that has resolved by 21 years are twice as likely to have an anxiety disorder.
Dr. Walker's study involved 754 children 8 to 15 years of age with FAP and no identifiable organic disease.
Patients and their mothers were interviewed at a pediatric gastrointestinal clinic, and underwent a multidimensional assessment of pain intensity, frequency, and duration, and the cognitive and affective aspects of their pain.
A cluster analysis identified 3 distinct groups of patients: the "high pain dysfunctional" group had intense frequent pain, high levels of catastrophizing, negative affect, and low levels of perceived efficacy (25% of the cohort); the "high pain adaptive" group consisted of patients who were trying to remain functional despite their pain (40% of the cohort); and the "low pain adaptive" group had minor infrequent pain, low levels of catastrophizing, high perceived efficacy, and little dysfunction. In this group, it was the parents' concern about the pain that brought the children to the clinic.
Nine years after enrolment, 379 patients (average age, 21 years) were contacted and reinterviewed about their abdominal pain, other pain, and psychiatric symptoms.
Novel Focus on Anxiety
In the high pain dysfunctional group, 60% of patients still had persistent abdominal pain; the rate was about half this in the other 2 groups, said Dr. Walker.
More than 45% of patients in the high pain dysfunctional group met the criteria for a current anxiety disorder, which is significantly more than in the other 2 groups (25% to 30%). A retrospective chart review revealed a 70% lifetime rate of anxiety disorders in this group.
"The majority of those with a lifetime anxiety disorder often had an onset prior to their FAP evaluation," she said, adding that almost 1 in 5 patients in the high pain dysfunctional group reported that they had lost a job because of illness.
Depressive symptoms were no higher in any of the groups than in the general population, which adds to the evidence that it is anxiety, not depression, that is driving this process.
"Poor outcomes were driven by anxiety-related processes, including threat appraisal, fear, and avoidance," she said.
"This is interesting because the GI world and the IBS [irritable bowel syndrome] world has focused, in adults, at least initially, more on depression than anxiety."
The study is the first to show different psychosocial profiles in pediatric FAP and to link them to prognosis.
She asked: "Can we identify high-risk groups efficiently in the busy pediatric clinic...and would treatment of anxiety improve these outcomes?"
A pilot study presented at the meeting partially answered this question, although the patients were adults.
Thirteen subjects, 18 to 65 years of age, with comorbid IBS and generalized anxiety disorder were treated for 12 weeks with duloxetine, an antidepressant that is also approved for diabetic neuropathic pain and other pain conditions, such as fibromyalgia.
"The goal of the study was to try to use 1 agent to treat both conditions. It's a lot better if 1 agent can target the neurobiology of both," said lead investigator Alicia Kaplan, MD, from the Department of Psychiatry at Allegheny General Hospital in Pittsburgh, Pennsylvania.
The primary outcome was change in the Clinical Global Impression (CGI) scale score; secondary outcomes were changes in the Hamilton Anxiety Rating Scale score, the IBS Quality-of-Life Scale score, and the IBS Symptom Severity Scale score.
Compared with baseline, a significant improvement was observed in CGI–Improvement (P < .000) and CGI–Severity (P < .000) scores. There were also significant reductions in anxiety (P < .001) and IBS symptom severity (P < .023), and improvements in quality of life with IBS (P < .012).
"The brain–gut connection is bidirectional, and 95% of our serotonin receptors are in the gut," said Dr. Kaplan.
"There's a connection between the brain and the gut that is causing these symptoms. Part of it may be anxiety, part of it may be irritable bowel, but sometimes antidepressants can help both."
Dr. Campo, Dr. Walker, and Dr. Kaplan have disclosed no relevant financial relationships.
Anxiety Disorders Association of America (ADAA) 32nd Annual Conference. Session 306R, presented April 13, 2012; poster 106, presented April 14, 2012.