CONTINUITY, CHANGE, PREDICTORS AND IMPACT OF ADHD SYMPTOMS IN PRESCHOOL CHILDREN WITH AUTISM: A PROSPECTIVE FOLLOW-UP STUDY AFTER TWO YEARS

Abstract

Background: Children with Autism Spectrum Disorder (ASD) and co-occurring clinically elevated Attention Deficit Hyperactivity Disorder (ADHD) symptoms have been associated with older age groups, greater ASD symptom severity, and poorer adaptive functioning. However, most studies conducted to date have been cross-sectional and it is unclear if these factors predicted later ADHD symptomatology, and if earlier ADHD symptoms have an impact on autistic children’s quality of life. Aims: The present study examined continuity and change in ADHD symptomatology after 2 years and investigated earlier predictors of later ADHD symptomatology. It explored whether changes in both ASD symptoms and adaptive functioning had an impact on the changes in ADHD symptomatology, and examined the role of earlier ADHD symptoms on autistic children’s quality of life. Method: Caregivers of 58 children with ASD aged 7 to 9 years (from earlier [T1] 103 4 to 6-year-old autistic children) completed caregiver-reported measures. Results: Findings showed overall continuity of ADHD symptoms reported at the mean score level over two years and also changes, as rates of autistic children scoring above the clinical cut-off for ADHD symptoms increased from 8.62% at T1 to 22.41% at T2. Earlier ADHD symptoms were found to predict later ADHD symptoms, and changes in ASD symptom severity across two years were found to have an impact on changes in ADHD symptomatology. Lastly, results also showed that autistic children’s earlier levels of adaptive functioning also had an impact on their quality of life after two years. Possible clinical implications and future directions for research are discussed.