Cortisol and social stressors in children with fragile X: A pilot study

Evidence of neuroendocrine dysfunction, behavioral features of social anxie ty and avoidance, and neuroanatomical abnormalities suggest that abnormal h ypothalamic-pituitary-adrenal (HPA) function may be a component of the frag ile X (fra X) syndrome. In this preliminary study, salivary cortisol levels of males (n = 8, mean age = 13.5 yr) and females (n = 7, mean age = 13.9 y r) with the fra X full mutation were studied for 3 days. Day 1 was an exper imental day, during which subjects experienced a Social Stressor task midmo rning. Days 2 and 3 were routine days, during which the subjects were engag ed in their typical activities. Saliva samples were collected before breakf ast, lunch, dinner, and bedtime. On the experimental day, the prelunch samp le collection occurred 30 and 90 minutes after the Social Stressor task. Co mpared with children's norms, the combined group of mates and females with fra X had significantly higher cortisol levels in the prelunch and the preb edtime samples for the routine days. Comparisons between the two fra X grou ps for the experimental day revealed similar diurnal patterns for cortisol level. However, compared with females with fra X, males with fra X had sign ificantly higher cortisol levels at two points during the day: 30 minutes a fter the social stressor and at bedtime. These preliminary data suggest tha t individuals with fra X have abnormal HPA function. Understanding the rela tions among HPA dysfunction, abnormalities in brain structure and/or functi on, and maladaptive behavior and cognition in fra X could inform the design of early interventions using pharmacological or environmental measures des igned to normalize neuroendocrine function. J Dev Behav Pediatr 21:278-282 2000. Index terms: fragile X syndrome, salivary cortisol, social stressors, neuroendocrine, hippocampus.