Working memory and math skills in children with and without ADHD.

OBJECTIVE: Children with attention-deficit/hyperactivity disorder (ADHD) frequently demonstrate deficits in working memory and in multiple domains of math skills, including underdeveloped problem-solving and computation skills. The Baddeley model of working memory posits a multicomponent system, including a domain-general central executive and two domain-specific subsystems-phonological short-term memory and visuospatial short-term memory. Extant literature indicates a strong link between neurocognitive deficits in working/short-term memory and math skills; however, the extent to which each component of working/short-term memory may account for this relation is unclear. METHOD: The present study was the first to use bifactor (S·I-1) modeling to examine relations between each working/short-term memory subcomponent (i.e., central executive, phonological short-term memory, and visuospatial short-term memory), ADHD symptoms, and math skills in a clinically evaluated sample of 186 children ages 8-13 (Myears = 10.40, SD = 1.49; 62 girls; 69% White/non-Hispanic). RESULTS: Structural equation modeling indicated that all three working/short-term memory components exert a significant and approximately equal effect on latent math skills (ß = .29-.50, all p < .05) and together explain 56% of the variance in children's math achievement (R² = .56). Exploratory analyses indicated that teacher-reported ADHD inattentive symptoms provided a small but significant contribution to predicting latent math skills (ΔR² = .07) and accounted for 24% of the central executive/math association. CONCLUSIONS: These findings suggest that math difficulties in children with ADHD and clinically evaluated children without ADHD are associated, in large part, with their neurocognitive vulnerabilities in working/short-term memory and, to a lesser extent, overt ADHD symptoms. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evaluating the Simple View of Reading for Children With Attention-Deficit/Hyperactivity Disorder.

The 'simple view of reading' is an influential model of reading comprehension which asserts that children's reading comprehension performance can be explained entirely by their decoding and language comprehension skills. Children with ADHD often exhibit difficulty across all three of these reading domains on standardized achievement tests, yet it is unclear whether the simple view of reading is sufficient to explain reading comprehension performance for these children. The current study was the first to use multiple indicators and latent estimates to examine the veracity of key predictions from the simple view of reading in a clinically-evaluated sample of 250 children with and without ADHD (ages 8-13, Mage=10.29, SD=1.47; 93 girls; 70% White/Non-Hispanic). Results of the full-sample structural equation model revealed that decoding and language comprehension explained all (R2=.99) of the variance in reading comprehension for children with and without ADHD. Further, multigroup modeling (ADHD, Non-ADHD) indicated that there was no difference in the quantity of variance explained for children with ADHD versus clinically-evaluated children without ADHD, and that the quantity of explained variance did not differ from 100% for either group. Sensitivity analyses indicated that these effects were generally robust to control for monomethod bias, time sampling error, and IQ. These findings are consistent with 'simple view' predictions that decoding and language comprehension are both necessary and together sufficient for explaining children's reading comprehension skills. The findings extend prior work by indicating that the 'simple view' holds for both children with ADHD and clinically-evaluated children without ADHD.

Central executive training for ADHD: Impact on organizational skills at home and school. A randomized controlled trial.

OBJECTIVE: The current randomized controlled trial (RCT) was the first to examine the benefits of central executive training (CET, which trains the working components of working memory [WM]) for reducing organizational skills difficulties relative to a carefully matched neurocognitive training intervention (inhibitory control training [ICT]). METHOD: A carefully phenotyped sample of 73 children with attention-deficit/hyperactivity-impulsivity disorder (ADHD; ages 8-13, M = 10.15, SD = 1.43; 20 girls; 73% White/Non-Hispanic) participated in a preregistered RCT of CET versus ICT (both 10-week treatments). Parent-rated task planning, organized actions, and memory/materials management data were collected at pretreatment, posttreatment, and 2-4 month follow-up; teacher ratings were obtained at pretreatment and 1-2 month follow-up. RESULTS: CET was superior to ICT for improving organizational skills based on teacher report (Treatment × Time interaction: d = 0.61, p = .01, BF10 = 31.61). The CET group also improved significantly based on parent report, but this improvement was equivalent in both groups (main effect of time: d = 0.48, p < .001, BF10 = 3.13 × 107; Treatment × Time interaction: d = 0.29, p = .25, BF01 = 3.73). Post hocs/preregistered planned contrasts indicated that CET produced significant and clinically meaningful (number needed to treat = 3-8) pre/post gains on all three parent (d = 0.50 -0.62) and all three teacher (d = 0.46 -0.95) subscales, with gains that were maintained at 1-2 month (teacher report) and 2-4 month follow-up (parent report) for five of six outcomes. CONCLUSIONS: Results provide strong initial evidence that CET produces robust and lasting downstream improvements in school-based organizational skills for children with ADHD based on teacher report. These findings are generally consistent with model-driven predictions that ADHD-related organizational problems are secondary outcomes caused, at least in part, by underdeveloped working memory abilities. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

[Formula: see text] Does training working memory or inhibitory control produce far-transfer improvements in set shifting for children with ADHD? A randomized controlled trial.

Children with ADHD show impairments in set shifting task performance. However, the limited available evidence suggests that directly training shifting may not improve shifting performance in this population. We hypothesized that this incongruence may be because impairments exhibited by children with ADHD during shifting tasks are due to deficits in other executive functions, as shifting tasks also engage children's working memory and/or inhibitory control abilities. This randomized controlled trial examined the extent to which neurocognitive training of working memory vs. inhibitory control can produce downstream (far-transfer) improvements in set shifting task performance. Children with ADHD ages 8-12 (M = 10.41, SD = 1.46; 12 girls; 74% White/Non-Hispanic) were randomized to either central executive training (CET; n = 25) or inhibitory control training (ICT; n = 29), two next-generation digital therapeutics previously shown to improve their intended neurocognitive targets. Two criterion set shifting tests were administered at pre- and post-treatment. Results indicated that ICT was superior to CET for improving shifting accuracy (treatmentxtime: p = .03, BF10 = 3.01, η2 = .09, d = 0.63). ICT was also superior to CET for improving shifting speed, albeit on only one of the two outcome tasks (p = .02, BF10 = 4.53, η2 = .08, d = 0.59). CET did not produce improvements in shifting speed or accuracy on either task (p > .52, BF01 > 2.62), but showed evidence for more general (non-shifting-specific) improvement in response times on one of the outcome tasks (shift trials, d = 0.70; non-shift trials, d = 0.68). Taken together, these findings confirm that inhibitory control is important for successful performance on shifting tests, and suggest that training inhibitory control may reflect a method for improving set shifting difficulties in children with ADHD.

Are Reading Interventions Effective for At-Risk Readers with ADHD? A Meta-Analysis.

OBJECTIVE: Utilizing a multi-level meta-analytic approach, this review is the first to systematically quantify the efficacy of reading interventions for school-aged children with ADHD and identify potential factors that may increase the success of reading-related interventions for these children. METHOD: 18 studies (15 peer-reviewed articles, 3 dissertations) published from 1986 to 2020 (N = 564) were meta-analyzed. RESULTS: Findings revealed reading interventions are highly effective for improving reading skills based on both study-developed/curriculum-based measures (g = 1.91) and standardized/norm-referenced achievement tests (g = 1.11) in high-quality studies of children with rigorously-diagnosed ADHD. Reading interventions that include at least 30 hours of intervention targeting decoding/phonemic awareness meet all benchmarks to be considered a Level 1 (Well-Established) Evidence-Based Practice with Strong Research Support for children with ADHD based on clinical and special education criteria. CONCLUSIONS: Our findings collectively indicate that reading interventions should be the first-line treatment for reading difficulties among at-risk readers with ADHD.

Central executive training for ADHD: Effects on academic achievement, productivity, and success in the classroom.

OBJECTIVE: Central executive training (CET) is a "Level 2" evidence-based treatment for improving ADHD-related executive dysfunction and behavioral symptoms, but the extent to which these gains extend to the disorder's well-documented academic difficulties is unknown. METHOD: Across two clinical trials, 108 children with attention-deficit/hyperactivity disorder (ADHD) 8-13 years old (M = 10.29, SD = 1.50; 32 girls; 75% White/Non-Hispanic) were treated with CET (n = 52), inhibitory control training (ICT; n = 29), or gold-standard behavioral parent training (BPT; n = 27). RESULTS: CET was superior to BPT and ICT (d = 0.62-0.88) for improving masked teacher perceptions of academic success, impulse control, and academic productivity at 1-2 months posttreatment. At 2-4-month follow-up, CET (d = 0.76) and ICT (d = 0.54) were superior to BPT for improving objectively-tested academic achievement overall (reading comprehension, math problem-solving, language comprehension), and CET was superior to ICT (d = 0.56) for improving math problem-solving. The significant benefits of CET on academic success, academic productivity, reading comprehension, and math problem-solving replicated across both trials and were clinically significant as evidenced by low number needed to treat estimates (Needed to Treat; NNT = 3-7) and significantly higher proportions of individual cases demonstrating reliable improvements in academic success/productivity (33%-36% vs. 0%-18%) and achievement (38%-72% vs. 18%-54%) across outcomes (all p ≤ .01). CONCLUSIONS: Results across the two trials provide strong support for the efficacy of CET for ADHD, and are consistent with model-driven hypotheses that academic difficulties in ADHD are due, in part, to these children's underdeveloped executive functioning abilities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).