Do ASD Symptoms at 2 Years Influence the Prediction of Childhood Sleep Problems and Anxiety from 2- to 8-Years?

Background: Research has demonstrated a link between sleep difficulties and anxiety amongst typically developing children and children with ASD. Both anxiety and poor sleep are common in children with ASD and they are 2-3 times more likely to experience sleep and anxiety problems than are typically developing children. Studies in typically developing children suggest that childhood sleep problems may predict anxiety later in childhood. However, few studies have explored this relationship longitudinally in young children or considered how ASD symptoms may affect these relationships.

Objectives: To examine the influence of early symptoms of ASD on childhood sleep problems and anxiety and the prediction of sleep problems and anxiety from 2- to 8-years of age.

Methods: Data were from the Western Australian Pregnancy Cohort (Raine) Project, which recruited 2900 pregnant women between 1989 and 1991, of whom 2868 were available for follow-up after their child’s birth; children were then followed at 1, 2 and 3 years and then every 2-3 years thereafter. Demographic information (108 items) on the mother, father and family at 16-18 weeks gestation was available, and from the 2-year follow-up, information on children’s behaviour was collected using the Child Behavior Checklist (CBCL).  For the current study the information extracted from the data base included relevant parent and family demographics (13 items), and information on children’s sleep, anxiety and ASD symptoms at 2-years and sleep and anxiety at 8-years from CBCL data collected at these ages.

Results:  Sleep, anxiety and ASD symptoms at 2-years and sleep and anxiety at 8-years were all significantly correlated.  Four hierarchical multiple regressions, two with sleep at 8-years and two with anxiety at 8-years as the dependent variables were conducted.  Mothers’ and fathers’ and family demographics, and the child’s gender were entered first into all regressions.  For the prediction of sleep at 8-years, sleep and anxiety at 2-years and anxiety at 8-years were entered into the first model, and ASD symptoms at 2-years was added after gender in the second model.  For the prediction of anxiety at 8-years, anxiety and sleep at 2-years and sleep at 8-years were entered for the first model and ASD symptoms at 2-years was added after gender in the second model.  All final models were significant. Anxiety at 2-years, sleep problems at 2-years and sleep problems at 8-years uniquely predicted anxiety at age 8, and sleep problems at age 2 and anxiety at 8-years uniquely predicted sleep problems at age 8, with each of the 8-year-old variables explaining the most variance. ASD symptoms at 2-years was a unique significant predictor of anxiety at age 8, but not sleep. Two demographic variables also contributed significantly to the prediction of sleep at 8-years.

Conclusions:  This study supports research showing that childhood sleep problems and anxiety are interrelated. Children who currently present with either poor sleep or anxiety are likely to experience difficulties with the other. Importantly, early ASD symptoms were related to both poor sleep and anxiety, and contributed significantly to anxiety later in childhood.