Abstract
Despite long-standing public and scientific interest in the phenomenon of sleep, the current decade has shown tremendous growth in our understanding of the sleep of children who have medical or developmental conditions. To accommodate, promote, and guide that growth, Journal of Pediatric Psychology, Clinical Practice in Pediatric Psychology, and Journal of Developmental and Behavioral Pediatrics have published coordinated special issues, encompassing >30 relevant articles. This article introduces the special issue in Journal of Pediatric Psychology, highlighting papers that illustrate how sleep problems are not only commonly comorbid with childhood medical and developmental conditions; they are also likely caused by and contribute to these conditions. In doing so, these coordinated special issues guide clinical care and reveal opportunities for future research.