Strengths and Weaknesses in the Intellectual Profile of Different Subtypes of Specific Learning Disorder

The present study analyzes whether and how the most common diagnoses within the specific learning disorder (SLD) category are characterized by different intellectual profiles. The issue is relevant to the current debate on the unitary versus decomposable nature of the SLD category and may help define specific interventions. Intellectual profiles were obtained using the Wechsler Intelligence Scale for Children–IV (WISC-IV) on 1,049 children diagnosed with SLD using the ICD-10 codes. Four major subsamples were compared: reading disorder, spelling disorder, disorder of arithmetical skills, and mixed disorder of scholastic skills. The four main WISC-IV indexes (verbal comprehension, perceptual reasoning, working memory, and processing speed) were considered. Results showed that all SLD subgroups share similar weaknesses in working memory and processing speed, but they also showed that the subgroups are characterized by partly different intellectual profiles. These specificities should be considered in the definition of SLD.

Intellectual Profiles in Children With ADHD and Comorbid Learning and Motor Disorders

Objective: Neurodevelopmental disorders, including Reading Disorder, Disorder of Written Expression, and Developmental Coordination Disorder, often co-occur with ADHD. Although research has identified increased functional impairment in the presence of these comorbid diagnoses, few direct comparisons of intellectual profiles have been conducted. Thus, the present study examined Wechsler Intelligence Scale for Children–Fourth Edition (WISC-IV) profiles of children with ADHD alone and with comorbid neurodevelopmental disorders. Method: Participants included 296 children with ADHD, ADHD with Developmental Coordination Disorder, and ADHD with Reading Disorder and/or Disorder of Written Expression. Results: Comparisons of these groups suggests children with ADHD and language-based Learning Disorders have poorer working memory than children with only ADHD. Furthermore, children with ADHD and Developmental Coordination Disorder perform relatively better on verbal compared with perceptual reasoning indexes. Conclusion: These intellectual profiles may have utility in identifying cognitive weaknesses inherent to these disorders and may be used to guide treatment intervention.