Executive control refers to top-down mental processes like working memory, inhibition, and cognitive flexibility that allow control of thoughts and behaviors. Deficits in these processes are central to ADHD.
If a child lacks cognitive control over their motor responses, they will have trouble stopping themselves from interrupting or jumping into an activity without thinking.
Training inhibitory control is thought to be an effective way to target andreduce impulsive behaviors.
Key Points
Rationale
Executive function deficits are central to ADHD, but training these abilities has shown little efficacy in past research (Rapport et al., 2013). This could reflect poor targeting – training protocols have not focused specifically on the precise executive functions empirically linked to ADHD behaviors and impairments.
This study continues the development of two new training protocols – CET targets the “working” components of working memory, whereas ICT targets inhibitory control.
Both abilities are implicated in ADHD (Chacko et al., 2014). Comparing them aims to determine their potential efficacy and mechanisms of change.
If improvements in the targeted executive function translate to symptomatic improvements, it would provide a paradigm-shifting approach totreating ADHD’s underlying pathologyrather than just managing behavioral symptoms. This moves the field closer to causal models and personalized medicine.
Replicated failures of past executive function training protocols necessitate comparing any new intervention to an adaptive active control training of the other executive function.
Demonstrating unique improvements in the targeted executive function and related behaviors would provide stronger evidence that the training engages its intended mechanism.
Method
Participants were randomized to 10 weeks of CET or ICT.
CET (Central Executive Training):
ICT (Inhibitory Control Training):
Dependent variablesassessed feasibility, proximal outcomes (working memory, inhibition), and distal outcomes (objective and subjective ADHD symptoms).
Sample
54 children with ADHD ages 8-12. 12 girls, 74% Caucasian. Diagnosed via clinical interview and rating scales. No differences between groups demographically or on pretreatment executive functioning.
Statistical Analysis
Results
Both treatments showed high feasibility and acceptance.
Parents perceived significant ADHD symptom improvements, especially for CET on the BASC-3 (CET d=0.96-1.42; ICT d=0.45-0.65).
Groups were equivalent on the ADHD-RS-5 (CET d=0.99-1.06; ICT d=0.70-0.94). CET produced superior working memory improvements (d=0.70-0.84), with large effects for CET (d=0.96-1.25) but weaker effects for ICT (d=0.26-0.41).
CET also improved go/no-go inhibition (d=0.47) despite no inhibition training. Stop-signal performance improved for both groups, limiting conclusions.
CET reduced objectively measured hyperactivity during working memory testing (d=0.47), but ICT did not (d=0.17).
CET also showed superior teacher-reported ADHD symptom reductions (d=0.52-0.66).
Formal mediation analyses indicated CET reduced hyperactivity via working memory gains.
Insight
The study provides important advances for ADHD intervention research.
First, CET successfully improved its intended mechanism –working memory. Significant mediation indicates these gains accounted for CET’s behavioral improvements, supporting working memory’s functional role in ADHD.
Second, cognitive and behavioral gains transferred to the classroom, demonstrating real-world benefits detectable even with small samples.
Third, parent-perceived improvements were largely maintained two months after treatment cessation, providing initial evidence that repeated practice may produce lasting gains.
These findings coincide with developmental data suggestingADHDinvolves 3-5 year delays in working memory-related neural networks – brief training may provide small “nudges” that accumulate over time.
Overall, CET met criteria as a “probably efficacious treatment” for ADHD, whereas determining ICT’s potential requires additional trials.
Both treatments may eventually provide independent or synergistic benefits as part of personalized medicine approaches addressing ADHD’s multi-faceted impairments.
Replicating and extending these initial findings could produce more generalized, pragmatic executive function training protocols that provide patients added access to treatment. Even modest improvements across enough people may have substantial public health impacts.
Strengths
This research has several strengths:
Limitations
There are also some limitations with this research:
Implications
Results substantiate executive function training as a promising evidence-based treatment approach for addressing ADHD’s underlying impairments.
Given psychostimulants do not strengthen cortical development and behavior therapies have limited generalization, executive function training that produces lasting neural changes may provide invaluable long-term outcomes.
The cognitive and behavioral improvements evident even with small samples and brief training support the continued optimization of CET.
If ongoing research replicates efficacy over larger, more diverse samples and reveals additive or synergistic benefits with behavior therapy, CET could provide a paradigm-shifting treatment model complementing traditional approaches.
An efficacious executive function training protocol could expand intervention access to the substantial number of families who refuse behavioral treatment and medication. Even modest improvements may have immense public health implications for millions of struggling children.
ICT requires further development but serves the vital purpose of beginning to parse apart shared and distinct treatment mechanisms. For CET, the critical next steps are determining optimal training doses, characterizing responders versus non-responders, and coupling training with biofeedback and/or medications to consolidate neural changes.
Investigating combined or sequential administration will test whether independently improving working memory and inhibition produces additive or synergistic benefits.
Broadly, these interventions represent an important evolution in ADHD precision medicine – continued optimization may soon transition executive function training into standard clinical practice.
References
Primary reference
Kofler, M. J., Wells, E. L., Singh, L. J., Soto, E. F., Irwin, L. N., Groves, N. B., Chan, E. S. M., Miller, C. E., Richmond, K. P., Schatschneider, C., & Lonigan, C. J (2020). A randomized controlled trial of central executive training (CET) versus inhibitory control training (ICT) for ADHD.Journal of Consulting and Clinical Psychology, 88(8), 738–756.https://doi.org/10.1037/ccp0000550
Other references
Chacko, A., Kofler, M., & Jarrett, M. (2014). Improving outcomes for youth with ADHD: A conceptual framework for combined neurocognitive and skill-based treatment approaches.Clinical Child and Family Psychology Review, 17(4), 368–384.https://doi.org/10.1007/s10567-014-0171-5
Rapport, M. D., Orban, S. A., Kofler, M. J., & Friedman, L. M. (2013). Do programs designed to train working memory, other executive functions, and attention benefit children with ADHD? A meta-analytic review of cognitive, academic, and behavioral outcomes.Clinical Psychology Review, 33(8), 1237–1252.https://doi.org/10.1016/j.cpr.2013.08.005
Simons, D. J., Boot, W. R., Charness, N., Gathercole, S. E., Chabris, C. F., Hambrick, D. Z., & Stine-Morrow, E. A. (2016). Do “brain-training” programs work?.Psychological Science in the Public Interest, 17(3), 103-186.https://doi.org/10.1177%2F1529100616661983
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Saul McLeod, PhD
BSc (Hons) Psychology, MRes, PhD, University of Manchester
Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.
Olivia Guy-Evans, MSc
BSc (Hons) Psychology, MSc Psychology of Education
Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.
