Autistic spectrum disorder symptoms in children and adolescents with attention-deficit/hyperactivity disorder: a meta-analytical review

Abstract

Background Research identifies highly variable prevalence estimates for autism spectrum disorder (ASD) in children and adolescents with attention deficit hyperactivity disorder (ADHD), particularly between community and clinical samples, warranting quantitative meta-analyses to investigate the true prevalence of ASD in children and adolescents with ADHD. Methods Studies were identified through a systematic literature search of PsycINFO, MEDLINE and Web of Science through January 2018. Twenty-two publications met inclusion criteria (total N = 61 985). Two random effects meta-analyses were conducted: (1) to identify the proportion of children and adolescents with ADHD that met criteria for ASD; and (2) to compare the severity of dimensionally-measured ASD symptomology in children and adolescents with and without ADHD. Results The overall pooled effect for children and adolescents with ADHD who met threshold for ASD was 21%. There was no significant difference between community samples (19%) and clinical samples (24%) or between US studies v. those from other countries. Children and adolescents with ADHD had substantially more dimensionally-measured ASD traits compared with those who did not have ADHD (d = 1.23). Conclusion The findings provide further evidence that ADHD and ASD are associated in nature. Clinical and research implications are discussed.

Inattention and hyperactive/impulsive component scores do not differentiate between autism spectrum disorder and attention-deficit/hyperactivity disorder in a clinical sample

“…High rates of co-occurrence between ASD and ADHD have been reported [5,6]. To date, few studies have examined the underlying relationship between the core domains of combined ASD and ADHD symptoms.…”

“…In population-based samples, 22% (95% confidence interval, 95% CI 17-26%) of people with ASD are clinically diagnosed with ADHD, with even higher rates in clinical samples (34%, 95% CI 29-39%) [5]. In children and adolescents with ADHD, 21% (95% CI 18-24%) reach the diagnostic threshold for ASD [6]. A better understanding of the relationship between ASD and ADHD is required in order to understand the mechanism of the co-occurrence, minimize diagnostic error, and personalize treatment opportunities.…”

Neural Correlates of Theory of Mind in Autism Spectrum Disorder, Attention-Deficit/Hyperactivity Disorder, and the Comorbid Condition

“…Autism spectrum disorder (ASD) is characterized by social communication difficulties and stereotypical/repetitive behaviors, while attention-deficit/hyperactivity disorder (ADHD) is characterized by age-inappropriate symptoms of inattention, hyperactivity, and impulsivity ( 1 ). Despite the distinct presentations, up to 55% of children and adolescents with the disorders meet both diagnostic criteria ( 2 , 3 ). Furthermore, reports of a co-occurrence of both disorders in adulthood may indicate its persistence ( 4 – 6 ).…”

Combining multivariate genomic approaches to elucidate the comorbidity between ASD and ADHD

“…Although both disorders are distinctive in terms of diagnostic criteria, there is a considerable overlap in symptomatology. Individuals with ASD commonly display inattention, impulsivity, and hyperactivity symptoms (4) and likewise, individuals with ADHD often have impaired social and communication skills (5–7). In addition, ASD and ADHD are frequently comorbid; approximately one third of children with ASD are also diagnosed with ADHD (8,9) and one fifth of children with ADHD meet diagnostic criteria for ASD (7).…”