“…Indeed, the high prevalence of sleep problems and their potential adverse effects on the psychosocial development of the child continue to remain major research and clinical issues in early childhood development (Sadeh, ; Sadeh & El‐Sheikh, ). Poor quality and insufficient amount of sleep have been repeatedly found to serve as risk factors for cognitive, behavioural, and emotional problems during preschool age and beyond (Bernier, Beauchamp, Bouvette‐Turcot, Carlson, & Carrier, ; Gregory & Sadeh, ; Reid, Hong, & Wade, ; Simola et al, ; Troxel et al, ; Wang et al, ; Whalen, Gilbert, Barch, Luby, & Belden, ); they are also related to internalizing pathology in adulthood (Gregory et al, ). As noted in the review of Gregory and Sadeh (), the last two decades have seen a substantial number of studies, both cross‐sectional and longitudinal, with clinical and non‐clinical samples, mostly address one side of possible effects, i.e., they explore the role of sleep on emotional and behavioural problems in later years.…”