Insomnia in children with ADHD : effects on functional outcome and moderators of treatment outcome in parent-based sleep focused intervention

Abstract

Insomnia is prevalent in children with ADHD. Studies suggested that children with ADHD and insomnia presented profound psychosocial impairments. However, it remained unclear which domain of psychosocial functioning was impaired and to what extent insomnia might contribute to the functional impairment in children with ADHD. Study 1 was a case-control study comparing 41 school-aged children with ADHD and insomnia with 21 age-mated children with ADHD only and 21 community-based controls. Participants completed Children's Sleep Habits Questionnaire (CSHQ) for assessing insomnia, Strengths and Weaknesses of Attention-Deficit/Hyperactivity Disorder Symptoms and Normal Behaviour Scale (SWAN) for measuring ADHD symptoms and Strengths and Difficulties Questionnaire (SDQ) for examining psychosocial impairments. Results showed that children with ADHD and insomnia had the most severe insomnia and ADHD symptoms as compared to the other groups. Even after controlling for the ADHD symptoms severity, children with ADHD and insomnia still showed the most severe psychosocial impairments in emotional, conduct and peer problems. Insomnia independently accounted for 3.9% of the variance of psychosocial impairments. Previous research showed that behavioural sleep intervention was effective in improving insomnia in children with ADHD. However, its impacts on alleviating the psychosocial impairments remained unclear. Moreover, studies exploring factors predicting the treatment response was limited. Study 2 recruited 42 school-aged children with ADHD and insomnia to receive a brief parent-based behavioural sleep intervention. Improvements of insomnia severity (CSHQ) and ADHD symptoms severity (SWAN), but not psychosocial outcomes (SDQ) at the post-intervention and 3-month follow-up were identified. Child’s sex, baseline insomnia severity, ADHD symptoms severity, attendee’s education level and parental psychological wellbeing, as measured by Depression, Anxiety and Stress Scale – Short Form (DASS-21), predicted the change of sleep onset delay. The findings from Study 1 and 2 highlighted the need to address insomnia in the context of ADHD and supported the efficacy of parent-based behavioural sleep intervention for children with ADHD and insomnia.