Later-born siblings of children with autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) have an elevated risk of being diagnosed with the same or the other disorder, according to a study published online Dec. 10 in JAMA Pediatrics.
Meghan Miller, Ph.D., from the University of California Davis in Sacramento, and colleagues used data extracted from medical records of two large health care systems to estimate recurrence risk and cross-aggregation in later-born siblings of children with ADHD or ASD. Data were included for 15,175 later-born siblings of children with ADHD (730 children), ASD (158 children), and no known diagnosis (14,287 children).
The researchers found that later-born siblings of children with ASD were more likely to be diagnosed with ASD or ADHD in the absence of ASD compared with later-born siblings of children without ADHD or ASD (odds ratios, 30.38 and 3.7, respectively). Later-born siblings of children with ADHD were more likely to be diagnosed with ADHD or ASD in the absence of ADHD compared with later-born siblings of children without a diagnosis (odds ratios, 13.05 and 4.35, respectively).
"Practitioners may wish to share such information with families given the potential relevance of monitoring social communication, attention, and behavioral regulation skills in later-born skills of children with ASD or ADHD," the authors write.