Sleep difficulties in children with Tourette syndrome and chronic tic disorders: a systematic review of characteristics and associated factors.

Sleep difficulties are common in children and young people with Tourette syndrome and chronic tic disorders (TS/CTD). However, it is unclear whether sleep problems can be considered typical of the TS/CTD phenotype or whether they reflect concomitant factors such as individual patient characteristics (e.g. medication use), underlying neurodevelopmental disorders and/or co-occurring psychiatric symptoms. To help address this question, this review systematically explored types and frequency of sleep problems in children and young people with TS/CTD, while also examining the heterogeneity and methodological quality of studies. Psycinfo, Ovid Medline, Embase, and Web of Science databases were searched using a range of terms relating to tics, sleep and co-occurring psychopathology. Studies were considered that included a sample of children with TS/CTD (n > 5) for whom sleep difficulties were measured. Eighteen studies met criteria for inclusion in the review. Findings supported the high prevalence of sleep difficulties in children with TS/CTD, though estimates of sleep difficulties ranged from 9.7% to 80.4%. Twelve studies reported on other factors affecting sleep in this patient group including tic severity, comorbid psychopathological or neurodevelopmental disorders and medication use. Studies varied in terms of methodology, sample characteristics and research quality, but most concluded that children with TS/CTD experienced high levels of sleep difficulties with children with co-occurring anxiety most at risk. The current review highlights the need for further empirical investigation of sleep in children with TS/CTS, with a view to informing understanding and clinical management.