NIH Abstract
Our goal is to understand biopsychosocial processes associated with pediatric chronic pain with the aim of informing prevention and treatment. Youth with chronic abdominal pain (CAP) have served as a prototype in our study of pain not associated with significant medically explained pathology. These youth are thought to be at risk for functional gastrointestinal disorders (FGIDs), headache, other chronic pain disorders, and psychiatric disorders as adolescents and adults. However, no prospective studies have systematically assessed these outcomes. Additional information is needed to characterize physical, emotional, and functional outcomes of CAP, discover risk factors for adverse outcomes, and identify psychological, behavioral, and physiological factors that may influence the course of CAP from childhood to adolescence and young adulthood. This application capitalizes on our existing landmark database of more than 800 patients evaluated for CAP at ages 8 through 15 years and a similar age control group of 350 well children. Our sample presents a unique opportunity to identify predictors of long-term health and psychosocial outcomes of pediatric onset CAP for individuals in our database who will be adolescents and young adults (ages 13 - 28 years) at follow-up. Former study participants with pediatric onset-CAP and those previously serving as well controls will be contacted for detailed psychosocial and laboratory follow-up assessment. Thus, we will evaluate CAP patients as they pass through the "age of risk" for several disorders associated with considerable impairment and health service use. We aim to (1) examine health and functional outcomes (including diagnostic criteria for FGIDs, chronic pain disorders, and psychiatric disorders) in adolescents and adults with pediatric onset CAP compared to well controls, (2) assess the relation between baseline risk factors and long-term outcomes and, (3) as a follow-up to our diary study that linked acute stress to CAP symptoms, use laboratory methods to examine experimentally the impact of acute stressors on symptom exacerbation and physiological reactivity across CAP and well controls, and identify potential moderators of the response to stressors.

Illness Behavior and Somatization in Children and Adolescents
Funded by the National Institute of Child Health and Development (1987-2006)
Principal Investigator: Lynn S. Walker, Ph.D.
Co-Investigators: Judy Garber, Ph.D., John W. Greene, M. D., D. Brent Polk, M.D., Craig A. Smith, Ph.D.

NIH Abstract
The long term goal of this program of research is to understand biopsychosocial processes associated with children's illness behavior (i.e., somatic complaints, disability, health service utilization). We are particularly concerned with children who maintain extensive illness behavior out of proportion to medical findings. Children with recurrent abdominal pain (RAP) serve as a prototype for our study of children with high levels of illness behavior not associated with significant organic disease. Our recent work showed that the within-subject correlation between daily stressors and somatic complaints was significantly stronger for children with RAP than for well children, suggesting that children with RAP may be distinguished from their peers by a tendency to react to stress with somatic symptoms. In the next stage of this research, our first major goal is to identify mechanisms linking environmental and somatic stressors to illness behavior in RAP. Specifically, using experimental methods in a laboratory setting, we will: (Aim 1) assess the influence of a challenging cognitive task on children's physiological activity, selective attention to somatic cues, and symptom reporting; and (Aim 2) assess the influence of visceral stimulation and parental responses on children's pain complaints. In addition, we will create an index of stress reactivity based on laboratory performance and will assess the utility of that index in predicting health outcomes. Our second major goal is to identify subgroups of RAP who may have different treatment needs. Specifically, we will: (Aim 3) identify diagnostic subgroups of patients with RAP and compare these with respect to symptomatology, psychosocial characteristics, and course of illness over 3 months, and (Aim 4) cross-validate a typology of pain coping profiles for patients with RAP and assess the utility of these profiles in predicting health outcomes. The proposed project combines self-report and psychophysiological measures, experimental laboratory methods, and a longitudinal design. Participants in the Baseline Assessment will include 396 patients with RAP and 842 Well children (ages 8-15). From these groups, children and their parents will be recruited for the Laboratory Computer Task (n =200) and the Laboratory Water Load Task (n = 220). Study results have the potential to yield insights into mechanisms linking stress to illness behavior in RAP and, in addition, to identify intervention targets that prepare children and their parents to better manage RAP.