Attention deficit hyperactivity disorder subtypes: Are there differences in academic problems?

A systematic review of attention deficit hyperactivity disorder (ADHD) and mathematical ability: current findings and future implications

BACKGROUND

Several recent behavioural and behavioural genetic studies have investigated the relationship between attention deficit hyperactivity disorder (ADHD) and mathematical ability. The aim of this systematic review was to provide an overview of these studies to date. An emphasis was placed on reviewing results that explored the association between mathematics and the two ADHD components of attention and hyperactivity-impulsivity separately.

METHODS

A systematic search of quantitative studies investigating the association between mathematics and ADHD was conducted across five databases (PsychINFO, Web of Science, PubMed, EMBASE, and Scopus). A total of 30 cross-sectional and four longitudinal studies were included in this review.

RESULTS

Narrative synthesis of the results was provided using PRISMA guidelines. Taken together, the studies pointed at substantial evidence for a negative association between ADHD symptoms and mathematical ability. This association was particularly marked for the inattentive component of ADHD than for the hyperactive-impulsive component. Evidence from twin studies also showed a significant genetic correlation between mathematics and ADHD, which was greater for the inattentive component of ADHD compared to the hyperactive-impulsive component.

CONCLUSIONS

The differential relationship of the hyperactivity-impulsivity and inattention domains with mathematics emphasises the heterogeneity within the disorder and suggests a partially different aetiology of the two ADHD domains. A better understanding of the aetiology of ADHD could help develop more efficient interventions aimed at the reduction of its symptoms. It could also offer an explanatory framework for shortcomings in achievement and inform the development of non-pharmacological intervention strategies.

Improving expressive writing skills of children rated for ADHD symptoms

The present study examines the expressive writing abilities of children described by their teachers as having Attention Deficit Hyperactivity Disorder (ADHD) symptoms and of matched controls and the effects of two types of facilitation. A group of 35 ADHD children and matched controls are given the task of composing a letter either under standard instructions or with facilitation (a guide scheme), preceded by a brief training on how to use the facilitation. Results show that both groups drew benefit from the guide scheme. Despite the fact that differences between groups were maintained after the training for the case of spelling errors, the poorer performance of ADHD children vanished. It is concluded that ADHD children have poor expressive writing skills, but this can be improved through the help of a guide scheme preceded by brief training.

ADHD and achievement: meta-analysis of the child, adolescent, and adult literatures and a concomitant study with college students

This article presents results from two interrelated studies. The first study conducted a meta-analysis of the published literature since 1990 to determine the magnitude of achievement problems associated with attention-deficit/hyperactivity disorder (ADHD). Effect sizes were significantly different between participants with and without ADHD (sample weighted r = .32, sample weighted d = . 71; p = .001). Effects were also examined according to the moderators of age, gender, achievement domain (reading, math, spelling), measurement method (standardized tests vs. grades, parent/teacher ratings, etc.), sample type (clinical vs. nonclinical), and system used to identify ADHD (DSM-III-R vs. DSM-IV). Significant differences emerged from the moderator comparisons. The second study, using averaged effect sizes from the first study as a baseline for comparison, investigated achievement levels for an understudied age group with ADHD, namely, college students. Unlike previous studies at the college level, the sample incorporated both student and parent ratings (N = 380 dyads). The results were comparable to outcomes from the meta-analysis for college students and adults. Analyses demonstrated modest (R = .21) but meaningful predictive validity across 1 year to end-of-first-year grades. However, unlike earlier studies with children and adolescents, student ratings were as predictive as parent ratings. Findings are discussed in terms of the impact of moderator variables on ADHD and achievement.

Hyperactivity and attention problems in a Swiss sample of school-aged children: effects of school achievement, child gender, and informants

OBJECTIVE

The sensitivity and tolerance regarding ADHD symptoms obviously differ from one culture to another and according to the informants (parents, teachers, or children). This stimulates the comparison of data across informants and countries.

METHOD

Parents and teachers of more than 1,000 school-aged Swiss children (5 to 17 years old) fill in Conners's questionnaires on ADHD. Children who are older than 10 years old also fill in a self-report questionnaire. Results are compared to data from a North American sample.

RESULTS

Swiss parents and teachers tend to report more ADHD symptoms than American parents and teachers as far as the oldest groups of children are concerned. Interactions are evidenced between school achievement, child gender, and informants. A relatively low rate of agreement between informants is found.

CONCLUSION

These results strengthen the importance to take into account all informants in the pediatric and the child psychiatry clinic, as well as in the epidemiological studies.

Comparison of ADHD symptom subtypes as source-specific syndromes

BACKGROUND

This study examines differences between the three subtypes of attention-deficit/hyperactivity disorder (ADHD), inattentive (I), hyperactive-impulsive (H), and combined (C), in a heterogeneous sample of 248 boys (ages 6 to 10 years) with emotional and behavioral problems who were recruited for participation in a diagnostic study.

METHOD

The boys and their mothers participated in an extensive evaluation that involved multiple assessments of cognitive, behavioral, academic, and family functioning. ADHD subtypes were defined on the basis of teacher alone, mother alone, and mother/teacher ratings of DSM-IV symptoms.

RESULTS

Results indicated ADHD symptom groups showed a differential pattern of impairment socially (H,C>I) and cognitively (I,C>H). The C and H groups were the most and least impaired overall, respectively, and all subtypes were differentiated from the nonADHD clinical control or NONE (N) group in a manner consistent with the primary findings. External validation of group differences was limited, and there were marked inconsistencies in the pattern of findings depending on how groups were defined. For the most part, although the mother/teacher grouping strategy (compared with either alone) captured a greater diversity of differences between subtypes, it also obscured some.

CONCLUSIONS

Observed findings are consistent with the notion that mothers and teachers interpret symptom statements in terms of behaviors that are most relevant for their daily concerns.

The disturbing effect of irrelevant information on arithmetic problem solving in inattentive children

Two studies explored the influence of irrelevant information on the problem-solving ability of children rated as inattentive by their teachers, on the basis of symptoms of attention deficit hyperactivity disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994). In the first study, 20 inattentive children, fourth and fifth graders, and 20 control children matched for IQ, gender, and schooling were administered 12-word arithmetic problems. Four problems included only essential information necessary for the problem's solution, whereas the other problems included irrelevant information, half at the beginning of the problem and half at the end. Although the inattentive children were equal to control children in their ability to solve problems with essential information, they performed more poorly in using appropriate problem-solving procedures when problems included irrelevant information, independent of its position. The second study compared the influence of numerical and verbal irrelevant information. Nineteen inattentive children and 18 control children, selected with similar criteria as Study 1, were presented with 12 problems, 6 with irrelevant numerical-arithmetic information and 6 with irrelevant verbal information. Both kinds of information produced a greater number of procedural errors in the inattentive group, but differences in calculation errors were less evident. Furthermore, inattentive children were more disturbed when the irrelevant information was verbal than when it was numerical, suggesting that inattentive children's difficulties in problem solving are partially due to an inability to inhibit irrelevant information, especially when it conveys a rich semantic knowledge.

Neurobehavioral assessment of attention deficit hyperactivity disorder in a Colombian sample

We present a factor analytic study of the Conners Rating Scales for parents and teachers in this article. A comparison is established with the original factor analytic studies (Conners, 1979a, 1979b) and the results obtained by Farré-Riba and Narbona (1997), using a Spanish sample. Five hundred and forty children, ages 4 to 17, were randomly selected in Manizales, Colombia. The shortened Spanish version of the Conners Parents Rating Scale (CPRS; Conners, 1979a) and the Conners Teacher Rating Scale (CTRS; Conners, 1979b) were used. Parsimonious factor analyses for both scales were developed. Three stable factors were found in the CPRS: hyperactivity, somatic symptoms, and inattention. Twenty-two out of 48 items were significantly saturated by these 3 factors. In the CTRS, 4 different factors were found that accounted for 63.5% of the total variance: uncontrolled temperament, inattention, hyperactivity, and difficulties in social relationships. Twenty out of 28 items were significantly saturated by these 3 factors. Factor structure was closer to the Spanish Farré-Riba and Narbona report than to the original findings. We concluded that the CPRS and the CTRS Spanish versions, when used by Colombian children and adolescents, do not seem to evaluate exactly the same underlying behavioral dimensions. We propose selecting only 22 items of the CPRS and 20 items of the CTRS (brief versions) for further epidemiological and clinical use.

Arithmetic disabilities and ADD subtypes: implications for DSM-IV

This study investigated whether specific academic deficits were associated with attention-deficit disorder (ADD) subtypes. Twenty students (ages 8-12) with attention-deficit disorder with hyperactivity (ADD/H) were compared to 20 students with attention-deficit disorder without hyperactivity (ADD/noH). Group differences were compared using a MANCOVA, and paired t tests were used to compare within-group differences. Dependent variables for the within-group differences were four achievement subtest scores from the Woodcock-Johnson Psycho-Educational Battery-Revised: Letter-Word Identification, Passage Comprehension, Calculation, and Applied Problems. Consistent with much of the previous research, no significant between-group differences were found on the achievement measures. Significant differences did, however, appear in the six within-group comparisons, all involving lower performance on the Math Calculations subtest. For students with ADD/H, only one comparison (with Math Applied Problems) reached significance. Students with ADD/noH, however, had significantly lower scores on the Calculation subtest compared to all of the other achievement subtests. These results provided additional support for the hypothesis that inattention exerts a specific and deleterious effect on the acquisition of arithmetic computation skills. These findings have important implications for the diagnosis and treatment of ADHD as conceptualized in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 1994), because they suggest that students with ADHD-Predominantly Inattentive Type may be at increased risk for arithmetic calculation deficits.

Neuropsychological and behavioral assessment of ADHD in seven- to twelve-year-old children: a discriminant analysis

We hypothesized that children with attention-deficit/hyperactivity disorder (ADHD) would underperform on neuropsychological tests that are sensitive to executive function impairments. We further proposed that a linear discriminant analysis using behavioral and neuropsychological variables as dependent variables would pinpoint the capability of behavioral questionnaires and neuropsychological tests to predict the correct classification of ADHD and control children. We designed a transversal study with 62 seven- to twelve-year-old children with ADHD and 62 Full Scale IQ-matched controls using two behavioral scales and 13 neuropsychological tests. Using analysis of variance and covariance with age and school achievement and multifactor analysis of variance, we found that behavioral variables established robust, statistically significant differences between groups (p < .001). Children with ADHD scored worse than controls on 31 out of 61 neuropsychological variables. Children with ADHD, however, obtained better scores that were statistically significant on WISC-R Comprehension and Picture completion. A linear discriminant analysis with nine behavioral variables correctly classified 100% of the participants in both groups. Another linear discriminant analysis using 10 neuropsychological variables correctly classified 85.48% of the participants in both groups. We propose a core battery of selected tests for assessing children with ADHD. The significance of cross-cultural analyses of different developmental disturbances is emphasized.

Comparing efficacies of neurocognitive treatment and homework assistance programs for children with learning difficulties

The purpose of the study was to analyze the relative efficacies of two treatments for children with learning difficulties. The first treatment consisted of multiple training components targeting specific cognitive and behavioral factors; the second treatment provided emotional support and supervision of school tasks. The participants were 94 Chilean schoolchildren (6 to 11 years of age). The efficacies were compared on (a) neurocognitive tests, (b) school achievement tests, and (c) behavior in school and at home. The results indicated that both groups improved on most of the outcome measures. The first group showed best results in parents' rating of home behavior, and the second group in reading. The findings also emphasized the importance of emotional support and the inclusion of a parents' group in treatment for children with learning difficulties.