Susan Dickerson Mayes

Learning Disabilities and ADHD Overlapping Spectrum Disorders

Clinical and psychoeducational data were analyzed for 119 children ages 8 to 16 years who were evaluated in a child diagnostic clinic. A learning disability (LD) was present in 70% of the children with attention-deficit/hyperactivity disorder (ADHD), with a learning disability in written expression two times more common (65%) than a learning disability in reading, math, or spelling. Children with LD and ADHD had more severe learning problems than children who had LD but no ADHD, and the former also had more severe attention problems than children who had ADHD but no LD. Further, children with ADHD but no LD had some degree of learning problem, and children with LD but no ADHD had some degree of attention problem. Results suggest that learning and attention problems are on a continuum, are interrelated, and usually coexist.

Learning, Attention, Writing, and Processing Speed in Typical Children and Children with ADHD, Autism, Anxiety, Depression, and Oppositional-Defiant Disorder

Learning, attention, graphomotor, and processing speed scores were analyzed in 149 typical control children and 886 clinical children with normal intelligence. Nonsignificant differences were found between control children and children with anxiety, depression, and oppositional-defiant disorder. Control children performed better than children with ADHD and autism in all areas. Children with ADHD and autism did not differ, except that children with ADHD had greater learning problems. Attention, graphomotor, and speed weaknesses were likely to coexist, the majority of children with autism and ADHD had weaknesses in all three areas, and these scores contributed significantly to the prediction of academic achievement.

Analysis of WISC-III, Stanford-Binet:IV, and academic achievement test scores in children with autism.

Nonverbal IQs were greater than verbal IQs for young children (3–7 years of age) on the Stanford-Binet:IV (n = 53). However, WISC-III verbal and nonverbal IQs were similar for older children, 6–15 years of age (n = 63). Stanford-Binet:IV profiles were generally consistent for the low-IQ (<80) and high-IQ (≥80) groups, with high scores on visual matching tests (Bead Memory and Quantitative Reasoning). The low- and high-WISC-III IQ groups both performed well relative to IQ on tests of lexical knowledge (Similarities, Information, and Vocabulary), but not on language comprehension and social reasoning (Comprehension). The low-IQ group did best on visuo-motor subtests (Object Assembly and Block Design), but the high-IQ group did not. The high-IQ group had significantly low scores on the Digit Span, Arithmetic, Coding, VMI, and WIAT Written Expression tests, suggesting attention and writing weaknesses.

Does DSM-IV Asperger's disorder exist?

DSM-IV criteria for autistic and Aspergers disorders were applied to 157 children with clinical diagnoses of autism or Aspergers disorder. All children met the DSM-IV criteria for autistic disorder and none met criteria for Aspergers disorder, including those with normal intelligence and absence of early speech delay. The reason for this was that all children had social impairment and restricted and repetitive behavior and interests (required DSM-IV symptoms for both autistic and Aspergers disorders) and all had a DSM-IV communication impairment (which then qualified them for a diagnosis of autistic disorder and not Aspergers disorder). Communication problems exhibited by all children were impaired conversational speech or repetitive, stereotyped, or idiosyncratic speech (or both), which are DSM-IV criteria for autism. These findings are consistent with those of 5 other studies and indicate that a DSM-IV diagnosis of Aspergers disorder is unlikely or impossible.

Ability Profiles in Children with Autism: Influence of Age and IQ

To understand the effect of IQ and age on ability in children with autism, psychological data were analyzed for 164 3- to 15-year-olds with autism (IQs 14-143). As age increased, so did IQ, which probably reflects both an actual increase in IQ over time and the likelihood that brighter children are diagnosed later. Early in life, 67 percent had normal motor and delayed speech milestones. Verbal IQ continued to lag behind non-verbal IQ during the preschool years. By school age, the gap between verbal and non-verbal IQs had closed. Visual reasoning exceeded graphomotor scores for all children, and surpassed IQ for most. Graphomotor scores were significantly below IQ for both high-IQ groups. For school-age children with low IQs, math, spelling, and writing scores were consistent with IQ and reading was above IQ. School-age children with high IQs had average reading, math, and spelling scores and a weakness in writing.

WISC-IV and WISC-III profiles in children with ADHD.

Wechsler Intelligence Scale for Children, 3rd and 4th editions (WISC-III n = 586 and WISC-IV n = 118), profiles were compared for children with ADHD and normal intelligence. Mean Verbal Comprehension Index (VCI) and Perceptual Organization/Perceptual Reasoning Index (POI/PRI) scores were significantly higher than Freedom From Distractibility/Working Memory Index (FDI/WMI) and Processing Speed Index (PSI), and Symbol Search was higher than Coding. FDI/WMI and PSI scores were similar on both tests, but VCI and POI/PRI were higher on the WISC-IV than on the WISC-III. Therefore, index discrepancies were greater for the WISC-IV, suggesting that the WISC-IV might be better than the WISC-III in delineating the strengths and weaknesses of children with ADHD. All children in the WISC-IV sample scored lowest on WMI or PSI, whereas only 88% of the WISC-III children scored lowest on FDI or PSI. Thus, the WISC-IV may be more helpful in diagnosing ADHD than the WISC-III.

ADHD Subtypes and Comorbid Anxiety, Depression, and Oppositional-Defiant Disorder: Differences in Sleep Problems

OBJECTIVE Sleep problems were analyzed in children with ADHD (Attention-deficit hyperactivity disorder). METHODS Scales were completed by parents of 135 control children and 681 children with ADHD combined type (ADHD-C) or inattentive type (ADHD-I) with or without comorbid oppositional defiant disorder (ODD), anxiety, or depression. RESULTS Children with ADHD-I alone had the fewest sleep problems and did not differ from controls. Children with ADHD-C had more sleep problems than controls and children with ADHD-I. Comorbid anxiety/depression increased sleep problems, whereas ODD did not. Daytime sleepiness was greatest in ADHD-I and was associated with sleeping more (not less) than normal. Medicated children had greater difficulty falling asleep than unmedicated children. CONCLUSIONS Differences in sleep problems were found as a function of ADHD subtype, comorbidity, and medication.

Child and parent reaction to the Three Mile Island nuclear accident.

Thirty-five local children and their parents were studied 1 1/2 years after the Three Mile Island (TMI) nuclear accident. On a standardized self-report measure, the children were found to have a level of residual anxiety that was not identified by their parents. These children also consistently reported stronger and more symptomatic responses to the TMI accident for themselves than their parents did for them. Child intensity-of-reaction scores were significantly related to mother-father discordance in mood and reaction to the event. Four of the children who were psychiatrically disturbed showed significantly high or low intensity-of-reaction levels.

Non-Significance of Early Speech Delay in Children with Autism and Normal Intelligence and Implications for DSM-IV Asperger’s Disorder

According to the DSM-IV, children with Asperger’s disorder do not have significant cognitive or speech delays, whereas children with autistic disorder may or may not. In our study, children with normal intelligence who had clinical diagnoses of autism or Asperger syndrome were divided into two groups: those with and without a significant speech delay. The purpose was to determine if clinically meaningful differences existed between the two groups that would support absence of speech delay as a DSM-IV criterion for Asperger’s disorder. No significant differences were found between the 23 children with a speech delay and the 24 children without a speech delay on any of the 71 variables analyzed, including autistic symptoms and expressive language. Results suggest that early speech delay may be irrelevant to later functioning in children who have normal intelligence and clinical diagnoses of autism or Asperger syndrome and that speech delay as a DSM-IV distinction between Asperger’s disorder and autism may not be justified.

Similarities and Differences in Wechsler Intelligence Scale for Children—Third Edition (WISC-III) Profiles: Support for Subtest Analysis in Clinical Referrals

Our study supports the reliability and validity of profile analysis in children with neurobiological disorders. Three mutually exclusive WISC-III profiles were identified that characterized the majority of children with autism (low coding or Freedom from Distractibility Index with low Comprehension), attention deficit hyperactivity disorder and learning disability (low Coding or FDI without low comprehension), and brain injury (low Performance without low Coding or FDI). The profiles suggest attention, writing, and performance speed deficits in autism, ADHD, and LD; global visual-motor problems in brain injury; and specific difficulty with language comprehension and social reasoning in autism. Children with anxiety, depression, and behavior disorders did not exhibit distinct profiles. Our profile analysis is based on the simple rank ordering of standard scores. The profiles are clinically useful because they may alert clinicians to certain diagnostic possibilities, they reveal characteristic strengths and weaknesses that have implications for educational intervention, and they are consistent with preliminary WISC-IV data.