Objective: Some children suffering attention deficit/hyperactivity disorder (ADHD) have similar social interaction and communication problems as those diagnosed to have autistic spectrum disorders (ASDs). This study aimed to compare autism spectrum symptoms in children according to ADHD subtypes and children without ADHD.
Method: ADHD and comorbid diagnoses were made using the Schedule for Affective Disorders and Schizophrenia for School-Age Children. The Social Responsiveness Scale (SRS), Childhood Behavior Checklist (CBCL), and ADHD Rating Scale (ADHD-RS) were used to evaluate symptoms.
Results: This study included 387 children: 238 in the ADHD group and 149 in the control group. Among those in the ADHD group, 28.6% were diagnosed to have ADHD inattentive subtype, 13.0% to be ADHD hyperactive/impulsive subtype, and 58.4% ADHD combined subtype. All the ADHD patients had higher SRS total and subscale scores than the control group (p<0.001). The SRS total and the social subscale scores were higher in the ADHD combined subtype than in the ADHD H/I subtype (p<0.05). After controlling for age, gender, and CBCL social withdrawal score, the difference in autism spectrum symptoms between the three ADHD subtypes was not significant. Assessment of the relationship between the ADHD-RS subscale scores and the SRS total and subscale scores based on Pearson’s correlation analysis showed that there was not a significant correlation between ADHD-RS subscale scores and any SRS score in any of the three ADHD subtypes.
Conclusion: The present study’s findings show that social withdrawal symptoms in those with ADHD might have effects on ASSs. However, no significant differences were found in ASSs between the ADHD subtypes when this effect was removed, all ADHD subtypes had a similar risk of ASSs, and ASSs might be accompanied by ADHD regardless of the symptoms of ADHD. To our own clinical experience, children with a combination of ADHD symptoms and ASSs are generally much more difficult to treat than children with ADHD alone. The present findings indicate the importance of evaluating ASSs, planning, and implementing treatment modalities such as early social skill training and interpersonal psychotherapy oriented for ASSs regardless of ADHD subtypes in all children with ADHD.