Symptom Profile of ADHD in Youth With High-Functioning Autism Spectrum Disorder: A Comparative Study in Psychiatrically Referred Populations

Abstract

Objective: To compare the clinical presentation of ADHD between youth with autism spectrum disorder (ASD) and ADHD and a sample of youth with ADHD only.

Method: A psychiatrically referred sample of autism spectrum disorder (ASD) youth with ADHD attending a specialized ambulatory program for ASD ( n = 107) and a sample of youth with ADHD attending a general child psychiatry ambulatory clinic ( n = 74) were compared.

Results: Seventy-six percent of youth with ASD met Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria for ADHD. The clinical presentation of ADHD in youth with ASD was predominantly similar to its typical presentation including age at onset (3.5 ± 1.7 vs. 4.0 ± 1.9; p = .12), distribution of diagnostic subtypes, the qualitative and quantitative symptom profile, and symptom severity. Combined subtype was the most frequent presentation of ADHD in ASD youth.

Conclusion: Despite the robust presentation of ADHD, a significant majority of ASD youth with ADHD failed to receive appropriate ADHD treatment (41% vs. 24%; p = .02). A high rate of comorbidity with ADHD was observed in psychiatrically referred youth with ASD, with a clinical presentation typical of the disorder.

Keywords: ADHD; autism spectrum disorder; youth.

Conflict of interest statement

Conflicts of Interest

All other authors have nothing to disclose.

Figures

Figure 1

Flow diagram of sample ascertainment process. Note. ASD = autism spectrum disorder; IQ = Intelligence quotient; HF-ASD = high-functioning ASD.

Figure 2

ADHD symptom profile in the context of ASD. Note. ASD = autism spectrum disorder. *p ≤ .05. **p ≤ .01. ***p ≤ .001.