Do Physiological Stress and Internalizing Alone and in Combination Predict Child Chronic Pain One Year Later?

Chronic or recurrent pain in childhood is a common and costly health problem, and increases the likelihood of experiencing chronic pain in adulthood. Existing evidence suggests that internalizing symptoms are a risk factor for the development of chronic pain in children and adults. Findings from a small body of research also points to a flattened diurnal cortisol profile, alone and in combination with internalizing symptoms, as a risk factor for future chronic pain among adults. The present study aimed to evaluate whether internalizing, a flattened diurnal cortisol profile, and their combination prospectively predict chronic pain in middle childhood. It was hypothesized that: 1) both internalizing and a flattened diurnal cortisol profile at age 8 would independently predict acquisition of chronic pain at age 9, controlling for age 8 pain; and 2) the combination of high internalizing and a flattened diurnal cortisol rhythm would predict greater risk of increased pain over time. Multilevel models of longitudinal data collected from a sample of 748 twin children revealed that internalizing symptoms and a flattened cortisol slope independently acted as prospective risk factors for increased chronic pain in childhood one year later. However, the interaction between internalizing and diurnal cortisol did not predict future increases in pain. Exploratory analyses evaluating symptoms of overanxiousness demonstrated that the interaction between overanxiousness and a flattened cortisol profile emerged as a marginally significant predictor of future pain. The current findings point to the role of psychological and physiological risk factors for the development of chronic pediatric pain, and may help to identify early targets for prevention efforts.