Learning Disorder Confers Setting-Specific Treatment Resistance for Children with ADHD, Predominantly Inattentive Presentation

Abstract

Attention deficit/hyperactivity disorder–predominantly inattentive presentation (ADHD-I) and specific learning disorder (SLD) are commonly co-occurring conditions. Despite the considerable diagnostic overlap, the effect of SLD comorbidity on outcomes of behavioral interventions for ADHD-I remains critically understudied. The current study examines the effect of reading or math SLD comorbidity in 35 children with comorbid ADHD-I+SLD and 39 children with ADHD-I only following a behavioral treatment integrated across home and school (Child Life and Attention Skills [CLAS]). Pre- and posttreatment outcome measures included teacher-rated inattention, organizational deficits, and study skills and parent-rated inattention, organizational deficits, and homework problems. A similar pattern emerged across all teacher-rated measures: Children with ADHD-I and comorbid ADHD-I+SLD did not differ significantly at baseline, but between-group differences were evident following the CLAS intervention. Specifically, children with ADHD-I and comorbid ADHD-I+SLD improved on teacher-rated measures following the CLAS intervention, but children with ADHD-I only experienced greater improvement relative to those with a comorbid SLD. No significant interactions were observed on parent-rated measures—all children improved following the CLAS intervention on parent-rated measures, regardless of SLD status. The current results reveal that children with ADHD-I+SLD comorbidity benefit significantly from multimodal behavioral interventions, although improvements in the school setting are attenuated significantly. A treatment-resistant fraction of inattention was identified only in the SLD group, implying that this fraction is related to SLD and becomes apparent only when behavioral intervention for ADHD is administered.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

¹ It is important to recognize that SLD diagnosis is usually conferred following full psychoeducational or neuropsychological evaluation and that the presence of significant academic achievement deficits indicates a suspected but not confirmed SLD diagnosis.

² Alternative summary scores, such as symptom severity scores, were also analyzed but did not change the pattern or interpretation of results.

³ Reexamination of the study models excluding participants with more than three symptoms of hyperactivity/impulsivity on the KSADS clinical interview (n = 3) did not change the pattern or interpretation of findings.

Additional information

Funding

This research was supported by National Institute of Mental Health Grant MH077671.Lauren Friedman and Melissa Dvorsky are supported by award number T32MH018261 from the National Institute of Mental Health (NIMH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.