“…Sleep problems are more frequent in children with behavioural problems (Arman et al, 2011), depression (Gregory, Rijsdijk, Lau, Dahl, & Eley, 2009), ADHD (Gruber, Sadeh, & Raviv, 2000) and in several developmental disorders (Annaz, Hill, Ashworth, Holley, & Karmiloff-Smith, 2011;Ashworth, Hill, Karmiloff-Smith, & Dimitriou, 2013). There are data pointing to a longitudinal relationship between early sleep difficulties and later behavioural problems in children (Gregory & O'Connor, 2002).…”