Elbe, P., Bäcklund, C., Vega-Mendoza, M., Sörman, D., Gavelin, H. M., Nyberg, L., & Ljungberg, J. K. (2023). Computerized cognitive interventions for adults with ADHD: A systematic review and meta-analysis. Neuropsychology, 37(5), 519–530. https://doi.org/10.1037/neu0000890
Key points
- This meta-analysis aimed to evaluate the efficacy of computerized cognitive training (CCT) interventions for adults with attention-deficit/hyperactivity disorder (ADHD).
- Nine randomized controlled trials (RCTs) with a total of 285 participants were included. The trials compared CCT interventions to control conditions like waitlist or active controls.
- A small but statistically significant effect of CCT was found for overall cognitive outcomes (g = 0.235). However, CCT did not significantly improve ADHD symptom severity or specific cognitive domains like executive functioning, cognitive speed, or working memory.
- The included studies had high risk of bias, so conclusions are limited. More rigorous RCTs are needed to determine the optimal CCT program type and length for adults with ADHD.
Rationale
ADHD persists into adulthood for many individuals, with prevalence around 4-5% in ages 18-44 years (Young & Goodman, 2016).
Adults with ADHD exhibit deficits in executive functions (EFs) like working memory compared to controls (Alderson et al., 2013).
Given these cognitive impairments, research has focused on computerized cognitive training (CCT) interventions aiming to improve EFs and working memory in ADHD (Shah et al., 2017).
CCT typically involves the computerized practice of cognitive tasks and intends to alleviate ADHD symptoms by enhancing attention skills (Klingberg et al., 2002). CCT has shown promise in children with ADHD, spurring interest in tailored interventions for adults.
However, CCT trials in the adult ADHD population have not yet been synthesized in a meta-analysis. This review filled this important gap by evaluating CCT efficacy on both cognitive and symptom outcomes in adults with ADHD.
Method
The literature was systematically searched to identify RCTs of CCT interventions for adults with ADHD.
Included studies had to have a mean age over 18 years and include adults with a primary ADHD diagnosis.
Eligible CCT interventions targeted cognition like EFs or working memory. Two independent reviewers extracted outcome data on overall cognition and ADHD symptom severity for meta-analysis.
Risk of bias was assessed using the Cochrane Risk of Bias 2 tool.
Sample
Across 9 included studies, there were 285 total participants (151 CCT, 134 control). Mean ages ranged from 21.1 to 41.6 years. Between 25-69% of participants were female. Most studies did not exclude pharmacotherapy use.
Statistical measures
Random-effects meta-analyses were conducted to synthesize overall cognitive outcomes, ADHD symptom severity, and cognitive domains like EFs, cognitive speed, and working memory.
Effect sizes were calculated as Hedge’s g, with 95% confidence intervals. Heterogeneity was assessed using I2 and tau2 statistics.
Results
- The meta-analysis showed a small but significant effect of CCT on overall cognitive outcomes (g = 0.235, 95% CI [0.002, 0.467], p = 0.048).
- However, CCT did not significantly impact ADHD symptom severity (g = 0.264, 95% CI [-0.005, 0.534], p = 0.055) or specific cognitive domains like EFs, speed, or working memory (all non-significant).
Insights and depth
This meta-analysis provides initial evidence that CCT may improve cognitive performance to a small degree in adults with ADHD.
However, the lack of symptom or functional improvements indicates limited clinical meaningfulness so far. Variability in CCT methods and outcome measures likely reduced power to detect effects.
More research is needed to identify the optimal CCT program type and duration for enhancing cognition and daily functioning in adult ADHD.
Strengths
- Systematic literature search and predefined inclusion/exclusion criteria
- Two independent reviewers for extraction and risk of bias assessment
- Use of established Cochrane RoB-2 tool for bias appraisal
- Preregistered protocol helps reduce bias
Limitations
- High risk of bias in included studies
- Small sample sizes restrict meta-analytic power
- Variability in CCT methods reduces ability to identify effective ingredients
- Few studies evaluated far transfer to daily functioning
Implications
These results provide tentative evidence that CCT may improve some cognitive skills in adults with ADHD.
However, inadequate study quality and small samples limit the strength of this conclusion. Clinicians should consider potential modest cognitive benefits but not assume CCT will improve ADHD symptoms or daily functioning yet.
Researchers need to conduct more high-quality, adequately powered RCTs systematically comparing different CCT programs. Identifying active ingredients and optimal duration is critical. Far transfer to symptom and functional outcomes should be evaluated.
Conclusion
In conclusion, this meta-analysis represents an initial synthesis of CCT trials for adult ADHD.
The findings suggest potential but limited benefits of CCT for cognitive performance at this stage.
More rigorous research is critically needed to clarify if tailored CCT programs can meaningfully improve cognition and symptoms for adults with ADHD.
Given the chronic daily impairments associated with adult ADHD, developing evidence-based non-pharmacological interventions is an important public health priority.
This review highlights the need for further research to unlock the full potential of CCT in this population.
References
Alderson, R. M., Kasper, L. J., Hudec, K. L., & Patros, C. H. (2013). Attention-deficit/hyperactivity disorder (ADHD) and working memory in adults: A meta-analytic review. Neuropsychology, 27(3), 287–302. https://doi.org/10.1037/a0032371
Klingberg, T., Forssberg, H., & Westerberg, H. (2002). Training of working memory in children with ADHD. Journal of Clinical and Experimental Neuropsychology, 24(6), 781–791. https://doi.org/10.1076/jcen.24.6.781.8395
Shah, T. M., Weinborn, M., Verdile, G., Sohrabi, H. R., & Martins, R. N. (2017). Enhancing cognitive functioning in healthly older adults: A systematic review of the clinical significance of commercially available computerized cognitive training in preventing cognitive decline. Neuropsychology Review, 27(1), 62–80. https://doi.org/10.1007/s11065-016-9338-9
Young, J. L., & Goodman, D. W. (2016). Adult attention-deficit/hyperactivity disorder diagnosis, management, and treatment in the DSM-5 era. The Primary Care Companion for CNS Disorders, 18(6), 1–18. https://doi.org/10.4088/PCC.16r02000
Learning check
- How could the limitations of small sample sizes be addressed in future research on CCT for adult ADHD? What challenges might researchers face in recruiting larger samples?
- What specific cognitive skills or processes should be targeted and measured in CCT trials for adult ADHD? How might these differ from those focused on in child ADHD interventions?
- If the benefits of CCT do not transfer well to real-world functioning, can it be considered an evidence-based treatment for adult ADHD? How much should clinical recommendations rely on symptomatic or functional improvements versus cognitive effects?
- How could factors like ADHD subtype (inattentive vs hyperactive), comorbid conditions, or medication status influence CCT outcomes? How can trials be designed to better evaluate moderators?
- What role should CCT have in a multimodal treatment approach for adult ADHD? What other psychosocial or pharmacological options should it be combined with?
