Overlapping sleep disturbances in persistent tic disorders and attention-deficit hyperactivity disorder: A systematic review and meta-analysis of polysomnographic findings

Introduction: Persistent tic disorders (PTDs) and attention-deficit hyperactivity disorder (ADHD) are common neurodevelopmental conditions which tend to co-occur. Both diagnoses are associated with sleep problems. This systematic review and meta-analysis investigates overlaps and distinctions in objective sleep parameters based on diagnosis (PTD-only, PTD + ADHD, and ADHD-only). Methods: Databases were searched to identify studies with objective sleep measures in each population. Metaanalyses were conducted using a random effects model. Results: Polysomnography was the only measure included in all three groups. Twenty studies met final inclusion criteria, combining PTD-only (N = 108), PTD + ADHD (N = 79), and ADHD-only (N = 316). Compared to controls (N = 336), PTD-only and PTD + ADHD groups had significantly lower sleep efficiency and higher sleep onset latency. PTD + ADHD also had significantly increased time in bed and total sleep time. No significant differences were observed between ADHD-only groups and controls. Discussion: Different sleep profiles appear to characterise each population. PTD + ADHD was associated with more pronounced differences. Further research is required to elucidate disorder-specific sleep problems, ensuring appropriate identification and monitoring of sleep in clinical settings.