Impact of working memory training on hot executive functions (decision-making and theory of mind) in children with ADHD: a randomized controlled trial

Background Children with attention deficit/hyperactivity disorder (ADHD) have deficits in working memory (WM) and in hot executive functions (EFs) that may be related. The main aim of this study was to analyze the efficacy of computerized Cogmed Working Memory Training™ (CWMT) on hot EF decision-making and theory of mind (ToM). Correlational analyses between WM and hot EFs at baseline were also performed to better clarify the nature of this interrelationship. Methods 66 children with combined-type ADHD, aged 7 to 12 years, were included. Participants were randomized (1:1) to an experimental group (CWMT) (n=36) or a control group (non-adaptive training). At baseline, 1-2 weeks, and 6 months after the intervention, participants were assessed using performance-based measures of WM (backward digit span, letter-number sequencing of WISC-IV, and backward spatial span of WMS-III), decision-making (Iowa Gambling Task), and ToM (Happe’s Strange Stories and Folk Psychology Test). Results Statistically significant correlations were found between WM and ToM measures at baseline, but not between WM and decision-making. On adjusted multiple linear regression analysis, there were no significant improvements in any of the outcome measures at either time point. Conclusions There was no relationship between WM and decision-making in ADHD. A relationship was found between WM and ToM, but CWMT did not show far-transfer effects on ToM deficits in ADHD. Other implications of these results are discussed.