Background: Sluggish cognitive tempo (SCT) recently experienced a resurgence of interest in children with ADHD, but only three small studies have investigated SCT in autism. Method: Mothers rated 1,436 children with autism, 1,056 with ADHD without autism, and 186 typical controls, 2-17 years, on six SCT items from the Pediatric Behavior Scale. Results: Almost half (49%) of children with autism scored 1.5 standard deviations or more above the typical SCT mean, as did 40% with ADHD-Inattentive and 31% with ADHD-Combined. The significantly greater prevalence in autism versus ADHD is largely explained by the high frequency of ADHD in autism and the increased risk of SCT when both disorders are present. However, the higher than normal prevalence of SCT in autism is not accounted for by co-occurring ADHD because SCT scores were higher than the norm in children with autism who did not have ADHD and SCT scores did not differ significantly between children with autism without ADHD and children with ADHD without autism. Conclusions: Previous research indicated SCT was associated with ADHD-Inattentive type, but our findings show that SCT is even more prevalent in autism. SCT is most common when autism and ADHD co-occur. Because autism without ADHD is rare (whereas ADHD without autism is not), it is important to assess both SCT and ADHD in children referred for autism evaluations and rule-out autism in children referred for ADHD. SCT may be another neurocognitive problem shared by children with autism and children with ADHD in need of assessment and intervention.
All Science Journal Classification (ASJC) codes
- Developmental and Educational Psychology
- Clinical Psychology
- Psychiatry and Mental health