Clinical Validity and Interpretation of the Gordon Diagnostic System in ADHD Assessments

Gordon Diagnostic System (GDS) data were analyzed for 165 referred children with ADHD combined type and 46 referred children without ADHD, 6–16 years of age. Results showed significant differences between children with and without ADHD on the GDS standard scores and the IQ-GDS differences scores. Using a GDS composite standard score of 13 points or more below IQ to classify children as having ADHD resulted in the highest diagnostic accuracy (86%), with positive predictive power equal to 91%, and negative predictive power 67%. Results for the GDS compared favorably with those reported for other continuous performance tests. The findings lend support to the GDS as a clinically useful component of an ADHD evaluation.     

Clinical validity and interpretation of the Gordon Diagnostic System in ADHD assessments.

Gordon Diagnostic System (GDS) data were analyzed for 165 referred children with ADHD combined type and 46 referred children without ADHD, 6-16 years of age. Results showed significant differences between children with and without ADHD on the GDS standard scores and the IQ-GDS differences scores. Using a GDS composite standard score of 13 points or more below IQ to classify children as having ADHD resulted in the highest diagnostic accuracy (86%), with positive predictive power equal to 91%, and negative predictive power 67%. Results for the GDS compared favorably with those reported for other continuous performance tests. The findings lend support to the GDS as a clinically useful component of an ADHD evaluation.     

Single-component microcomputer-driven assessment of attention

The Gordon Diagnostic System (GDS) is a single-component microcomputer-based instrument that can be used to administer 11 psychological tests. The game-like tasks provide objective data for evaluating possible attention-deficit hyperactivity disorder or other conditions that affect a person’s ability to sustain attention and exert self-control. The core of the instrument is an integrated circuit with a microprocessor, a random access memory, and an erasable, programmable read-only memory (EPROM). It can be programmed with an IBM PC and an EPROM programmer. The assembly language source is compiled into machine language, which is used to simulate the GDS on the IBM PC or is “burned” into the ROM. The memory is erasable with ultraviolet light, so revisions can be made easily. The GDS illustrates that “custom” programming a ROM is not limited to large industrial concerns, and that it can be done within small research groups.     

WISC-III Cognitive Profiles in Children with ADHD: Specific Cognitive Impairments and Diagnostic Utility

This study aimed to investigate the presence of specific cognitive impairments and the diagnostic utility of the WISC-III in children with ADHD. Ninety-eight children with ADHD and 81 children without ADHD matched by age and gender (control group), between the ages of 6 and 12?years, participated in the study. Children with ADHD revealed the most pronounced deficits in the subtests tapping working memory and processing speed. Freedom from Distractibility was the cognitive profile most impaired and that showed the highest diagnostic accuracy to discriminate children with ADHD. The optimal cutoff scores of the most common WISC-III cognitive profiles revealed greater diagnostic accuracy than the traditional approach of full or partial profiles. Taken together, these results suggested that in the context of a comprehensive psychological assessment, the WISC may provide knowledge about the specific cognitive strengths and weaknesses that characterize this disorder and may be useful in the decision-making process relative to ADHD diagnosis.     

The Relationship Between Performance on the Gordon Diagnostic System and Other Measures of Attention

Tests purporting to measure attention were administered to college students to examine their relationship to three relatively new tests of attention from the Gordon Diagnostic System (GDS). All subjects received the Standard Delay, Vigilance, and Distractibility Tests of the GDS. In addition, 69 of 136 subjects received the Digit Span, Arithmetic, and Digit Symbol subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and Kagan's Matching Familiar Figures Test. After the GDS, the other 67 subjects received the Visual Span subtest of the Wechsler Memory Scale-Revised (WMS-R), and the Stroop. Replication (across two studies) and gender influences were not evident on GDS performance. Performance data on this test for these 136 college students, collapsed across replication and gender, are presented. Although within-test correlations were strong, correlations between tests were weak. A ceiling effect on the Vigilance task may have effected its correlations with other tests. Results suggest that the GDS tasks are not substitutes for commonly used tests of attention, but may be useful as an additional source of information in the assessment of attention.     

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.     

WISC-R subtest but no overall VIQ-PIQ difference in Dutch children with PDD-NOS

VIQ-PIQ differences have been studied in children with autism and Asperger syndrome but have not been studied in a separate group of children with PDD-NO, although, PDD-NOS has a much higher prevalence rate than autism and deficits in communication and social interaction are severe. The Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered to 100 children, aged 6-12 years, with PDD-NOS (n = 76), autism (n = 13), and Asperger syndrome (n = 11). PDD-NOS was diagnosed using explicit research criteria. No overall differences between VIQ and PIQ were found in PDD-NOS and autism. Peaks in the subtest scores on Information, Similarities, Picture Arrangement, and Mazes, and troughs in the subtest scores on Comprehension, Digit Span, and Coding were demonstrated in children with PDD-NOS. Their score on the Freedom from Distractibility factor was lower than the scores on the Verbal Comprehension factor and the Perceptual Organization factor. Children with PDD-NOS seemed to have a similar VIQ-PIQ profile as children with autism, and on the subtest level children with PDD-NOS showed some similarities to children with Asperger syndrome or autism. It was not possible to distinguish PDD-NOS from autism or Asperger syndrome by using IQ scores.     

Conners’ continuous performance test (CCPT-II) in children with ADHD,ODD, or a combined ADHD/ODD diagnosis

The current study investigated if results on the Conners’ Continuous Performance Test (CCPT-II) could discriminate between children with ADHD (n = 59), ODD (n = 10), ADHD+ODD (n = 15), and normal controls (n =160), and how the results are associated with and explained by the intellectual function of the child. The sample was derived from the Bergen Child Study (BCS), a longitudinal, ongoing, population-based study of children’s development and mental health. CCPT-II performance did not differentiate between the three diagnostic groups (i.e., ADHD, ODD, and ADHD+ODD). Children with ODD (with or without comorbid ADHD) did not differ from children in the control group on any CCPT-II parameters. Children with ADHD made statistically significant more errors of omissions and showed a more variable response time to targets than the control group. The correlations between CCPT-II measures and IQ were mild to moderate, and there was a statistically significant group difference in IQ: Children with ADHD, and children with ADHD+ODD, obtained lower IQ scores than normal controls. A hierarchical multiple regression analysis showed that IQ, but not diagnostic group status, was significant predictors of CCPT-II performance. CCPT-II performance should be interpreted with caution when assessing ADHD and/or ODD in children.     

WISC-R Subtest But No Overall VIQ–PIQ Difference in Dutch Children with PDD-NOS

VIQ–PIQ differences have been studied in children with autism and Asperger syndrome but have not been studied in a separate group of children with PDD-NO, although, PDD-NOS has a much higher prevalence rate than autism and deficits in communication and social interaction are severe. The Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered to 100 children, aged 6–12 years, with PDD-NOS (n = 76), autism (n = 13), and Asperger syndrome (n = 11). PDD-NOS was diagnosed using explicit research criteria. No overall differences between VIQ and PIQ were found in PDD-NOS and autism. Peaks in the subtest scores on Information, Similarities, Picture Arrangement, and Mazes, and troughs in the subtest scores on Comprehension, Digit Span, and Coding were demonstrated in children with PDD-NOS. Their score on the Freedom from Distractibility factor was lower than the scores on the Verbal Comprehension factor and the Perceptual Organization factor. Children with PDD-NOS seemed to have a similar VIQ–PIQ profile as children with autism, and on the subtest level children with PDD-NOS showed some similarities to children with Asperger syndrome or autism. It was not possible to distinguish PDD-NOS from autism or Asperger syndrome by using IQ scores.     

Pathways from Birth Weight to ADHD Symptoms through Fluid Reasoning in Youth with or without Intellectual Disability

Although individual differences in fluid reasoning reliably mediate predictions of attention-deficit/hyperactivity disorder (ADHD) symptoms from birth weight in youth with typical cognitive development (TD), it is unknown if this indirect effect operates similarly in the development of ADHD symptoms secondary to intellectual disability (ID). Thus, we evaluated mediation by fluid reasoning in a longitudinal sample of 163 youth (45% female) with (n = 52) or without (n = 111) ID who were followed prospectively from age 5 to age 13. At age 9, youth completed the Arithmetic subtest of the Wechsler Intelligence Scale for Children, a measure of fluid reasoning. At ages 9 and 13, mothers and teachers separately rated youth ADHD symptoms and mothers completed a diagnostic interview. Mediation was tested via path analysis with bootstrapped confidence intervals, and moderated mediation estimated whether indirect effects differed between ID and TD youth or based on youth IQ. Controlling for demographic factors and age 9 ADHD symptoms, age 9 Arithmetic mediated birth weight and multi-method/informant age 13 ADHD symptoms, such that birth weight positively predicted Arithmetic, which negatively predicted ADHD symptoms. Neither ID status nor IQ moderated the observed indirect effect through Arithmetic, suggesting that it was similar for ID and TD youth as well as across the range of youth IQs. These findings support previous evidence that fluid reasoning, as measured by Arithmetic, may causally mediate birth weight and ADHD symptoms, and suggest that this pathway operates similarly with respect to the development of ADHD symptoms in youth with ID.     

Four tables for the statistical interpretation of factor scores on the Wechsler intelligence scale for children—Revised (WISC-R)

When the Wechsler Intelligence Scale for Children–Revised (WISC-R) is analyzed into three factors (Verbal Comprehension, Perceptual Organization, and Freedom From Distractibility), the clinician has the choice of expressing each factor as either a deviation quotient (an IQ analog) or a factor score (the arithmetic mean of the constituent subtests). For the clinician who wishes to use factor scores instead of deviation quotients, four tables are presented that provide (1) the percentile equivalents of factor scores; (2) the significance of differences between factor scores; (3) the frequency with which specified discrepancies occur; and (4) the significance of differences between a factor score and the scaled score of a constituent subtest.     

Construct validity of Wechsler factor scores.

The construct validity of the Verbal Comprehension. Perceptual Organization, and Freedom from Distractibility factor scores was examined in a sample of school-aged referred children. Examination of correlations between factor scores and neuropsychological and achievement tests generally supported the construct validity of the factors. The Verbal Comprehension factor was associated with verbal, quantitative, and concept-formation abilities. The Perceptual Organization factor was related to nonverbal concept formation, tactual performance, and visual attention. The Freedom from Distractibility factor demonstrated a complex pattern of correlations and appeared to reflect a range of abilities including quantitative, language, attentional, and concept formation.     

I. Validity of WISC-R factor scores in predicting achievement and attention for four sociocultural groups

The predictive validity of WISC-R factor scores was examined with samples from the four sociocultural groups of Anglo, Black, Chicano, and native American Papago. The Full Scale IQ and Verbal Comprehension (VC) factor scores were significantly better predictors of achievement as measured by teacher ratings and the Metropolitan Achievement Test. The Perceptual Organization and Freedom from Distractibility (FD) factor scores were also significantly related to achievement, but at a lower level than Full Scale and VC. The correlations of the WISC-R and achievement measures were nearly the same for three of the four groups (exception was native American Papago). The relationship of the FD factor score to ratings of attention was statistically significant, but relatively low. Cautions in interpreting FD as a measure of attention were recommended due to overlap of distributions and low proportion of variance in attention accounted for by FD.     

Accuracy of Reported Community Diagnosis of Autism Spectrum Disorder

To compare community diagnoses of Autism Spectrum Disorder (ASD) reported by parents to consensus diagnoses made using standardized tools plus clinical observation. 87 participants (85% male, average age 7.4 years), with reported community diagnosis of ASD were evaluated using the Autism Diagnostic Observation Schedule) (ADOS-2), Differential Ability Scale (DAS-II), and Vineland Adaptive Behavior Scales (VABS-II). Detailed developmental and medical history was obtained from all participants. Diagnosis was based on clinical consensus of at least two expert clinicians, using test results, clinical observations, and parent report. 23% of participants with a reported community diagnosis of ASD were classified as non-spectrum based on our consensus diagnosis. ASD and non-spectrum participants did not differ on age at evaluation and age of first community diagnosis. Non-verbal IQ scores and Adaptive Behavior Composite scores were significantly higher in the non-spectrum group compared to the ASD group (104.5?±?21.7 vs. 80.1?±?21.6, p?<?.01; 71.1?±?15 versus 79.5?±?17.6, p?<?.05, respectively). Participants enrolled with community diagnosis of PDD-NOS were significantly more likely to be classified as non-spectrum on the study consensus diagnosis than Participants with Autism or Asperger (36% versus 9.5%, Odds Ratio?=?5.4, p?<?.05). This study shows suboptimal agreement between community diagnoses of ASD and consensus diagnosis using standardized instruments. These findings are based on limited data, and should be further studied, taking into consideration the influence of DSM 5 diagnostic criteria on ASD prevalence.     

Differences in intelligence between nondelinquent and dropout delinquent adolescents

This study examined differences in intelligence between dropout delinquent adolescents and nondelinquent adolescents in Israel. It was part of research aimed at using psychological tests to characterize dropout delinquents. The participants, 215 adolescents at a psychoeducational center, were divided into three groups and were tested using the WISC-R: dropout delinquent adolescents living in residential institutions, dropout delinquent adolescents living at home, and nondelinquent adolescents living at home and enrolled in the formal education system. Results showed significant differences among the three groups in Verbal IQ, Performance IQ, Total IQ, and the Freedom from Distractibility factor, and pointed out the relative weakness of the dropout delinquent groups.     

The Use of the Devereux Scales of Mental Disorders in the Assessment of Attention-Deficit/Hyperactivity Disorder and Conduct Disorder

The present study was designed to gather validity data on the Devereux Scales of Mental Disorders (DSMD) for distinguishing among children and adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD; N = 32), Conduct Disorder (CD; N = 34), or no clinical diagnosis (NC; N = 65). Three types of indicators were compared: (a) DSMD scale, composite, and total scores, (b) the number of ADHD or CD-related items endorsed, and (c) diagnostic efficiency statistics (e.g., sensitivity, positive and negative predictive power). The clinical groups did not differ significantly from each other, but both were significantly higher than the NC group on all DSMD scales. Moreover, there were significant differences between the ADHD and the CD groups on the number of respective ADHD and CD-related items endorsed. A cut-off of seven to eight items yielded the best discrimination between the two diagnostic groups. Diagnostic efficiency statistics indicate that the DSMD may be effective at differentiating between similar disruptive behavior disorders.     

Concurrent validity of the WISC-R factor scores

This study investigated the efficacy of predicting academic achievement as measured by the Wide Range Achievement Test using the factor scores of the Wechsler Intelligence Scale for Children-Revised as potential predictors. Both instruments were administered to 200 school children referred for psychological evaluations. Factor scores for the WISC-R were computed according to equations provided by Gutkin (1978). These factor scores then were regressed in a stepwise manner on the Reading, Spelling, and Arithmetic standard scores from the Wide Range Achievement Test. Stepwise regressions also were performed using the traditional Verbal and Performance IQs as the potential predictors. A comparison was made between the results obtained by use of the factors or the more common scores. The results indicated that the Freedom From Distractibility factor score significantly aided in the prediction of Reading and Spelling achievement and was of primary importance in predicting Arithmetic achievement. When the stepwise results using the different scores were contrasted, the factor scores accounted for appreaciably more variance in Arithmetic than did the traditional Verbal and Performance IQs. Derived regression equations are reported along with a discussion of the interpretability of the Freedom From Distractibility factor.     

Stability and Change of ODD,CD and ADHD Diagnosis in Referred Preschool Children

Longitudinal studies have shown that preschool children’s diagnosis of Oppositional Defiant Disorder (ODD), Conduct Disorder (CD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are likely to persist into school age. However, limited attention has been paid to instability of diagnosis. The aim of the present study, therefore, was to investigate both stability and change of ODD, CD and ADHD diagnosis in children aged 3.5–5.5 years. For diagnosing these disorders, a semi-structured diagnostic parent interview, i.e., the Kiddie-Disruptive Behavior Disorder Schedule (K-DBDS), was used at the first assessment and at follow-up assessments (9 and 18 months). Five diagnostic stability groups (chronic, partial remission, full remission, new onset, no diagnosis) were compared with regard to impairment and number of symptoms. Participants were referred preschool children with externalizing behavioral problems (N?=?193; 83 % male) and typically developing (TD) children (N?=?58; 71 % male). Follow-up assessments allowed to distinguish children belonging to the chronic group of ODD, CD or ADHD from those belonging to one of the remission groups. In addition, there was a substantial number of children with a new onset diagnosis. In conclusion, as a complement to studies showing stability of ODD, CD and ADHD diagnosis into school age, present findings point to changes of diagnosis in the preschool and early school period. Diagnostic reassessments therefore are needed in this age group.     

Correspondence and disparity in the self- and other ratings of current and childhood ADHD symptoms and impairment in adults with ADHD

Experts recommend that clinicians evaluating adults for attention-deficit/hyperactivity disorder (ADHD) obtain information from others who know the patient well. The authors examined correspondence between the self- and other-ratings of ADHD symptoms and impairment using 3 groups of adults recruited on the basis of their severity of ADHD: ADHD diagnosis (n = 146), clinical controls self-referring for ADHD but not diagnosed (n = 97), and community controls (n = 109). The influences of diagnostic group, informant relationship, sex of participant, IQ, and comorbid anxiety and depression on self-informant disparities were also examined. Results indicated moderate to high agreement (.59-.80) between self and others on current functioning and slightly lower levels (.53-.75) between self- and parent ratings of childhood functioning. Examination of difference scores between self- and other ratings revealed small mean disparities (-0.1 to +5.0 points) but substantial variation (SDs = -2.4 to 8.9 points) for both current and childhood ratings. Clinic referrals not diagnosed with ADHD, particularly women, had higher disparities than was evident in the ADHD and community groups. Age, IQ, and education were not associated with disparities in most ratings. Higher anxiety, in contrast, was associated with greater disparities on all current and childhood measures of both ADHD and impairment.     

Reporting Diagnostic Scores in Educational Testing: Temptations,Pitfalls, and Some Solutions

Diagnostic scores are of increasing interest in educational testing due to their potential remedial and instructional benefit. Naturally, the number of educational tests that report diagnostic scores is on the rise, as are the number of research publications on such scores. This article provides a critical evaluation of diagnostic score reporting in educational testing. The existing methods for diagnostic score reporting are discussed. A recent method (Haberman, 2008a Haberman, S. J. 2008a. When can subscores have value?. Journal of Educational and Behavioral Statistics, 33: 204–229. [Crossref], [Web of Science ®] , [Google Scholar]) that examines if diagnostic scores are worth reporting is reviewed. It is demonstrated, using results from operational and simulated data, that diagnostic scores have to be based on a sufficient number of items and have to be sufficiently distinct from each other to be worth reporting and that several operationally reported subscores are actually not worth reporting. Several recommendations are made for those interested to report diagnostic scores for educational tests.