May 22, 2024

Meta-analysis from Worldwide Data Finds Greater Co-occurrence of Epilepsy and ADHD Than Expected

Noting that the degree of comorbidity (co-occurrence) between epilepsy and ADHD “has never been quantified based on a systematic review with meta-analysis,” a Chinese study team based at Wuhan university has just reported findings based on doing just that. 

Their systematic search of the peer-reviewed medical literature yielded 17 studies examining the prevalence of epilepsy among persons with ADHD, and 49 studies measuring the prevalence of ADHD among persons with epilepsy.

According to the Apple dictionary app, epilepsy is “a neurological disorder marked by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain.” Its lifetime prevalence in the general population is about 0.76%, or about one in every 130 persons.

Meta-analysis of 17 studies with a combined total of over 900,000 participants spread over twelve countries on five continents yielded an epilepsy prevalence estimate of 3.4% among individuals with ADHD, or well over four times the prevalence in the general population. There was no sign of publication bias, but variability (heterogeneity) among studies was extremely high.

The worldwide prevalence of ADHD in children, on the other hand, is about 7.2%, affecting roughly one in fourteen.

Meta-analysis of 49 studies with a combined total of 172,206 persons from 16 countries on five continents reported an ADHD prevalence of just over 22% among persons with epilepsy. However, heterogeneity among studies was extremely high, and there was very strong evidence of publication bias. 

Using the trim-and-fill correction for publication bias yielded a reduced estimate of 16%, which is still over twice the prevalence in the general population.

Furthermore, the authors noted, “Given that the large sample studies in this study are basically population-based studies and the small sample studies are hospital-based studies, there is also the possibility of Berkson’s bias. Specifically, patients with comorbidities are more likely to need help or seek medical advice. This possibility would yield a higher comorbidity rate in hospital-based studies.”

And that is exactly what emerged from subgroup analysis. The prevalence of ADHD in epilepsy among the hospital-based studies was 27.1%, over twice the 13.2% prevalence reported from the 13 population-based studies. The largest population-based study, a U.S. study with over 114,000 participants, yielded a prevalence of only 3.5%.

The authors cautioned that the very high degree of heterogeneity between studies indicates “it is inappropriate to consider the summary effect as representative of the real effect.”

Shun, Wang & Yao, Baozhen & Haiju, Zhang & Xia, Liping & Yu, Shiqian & Peng, Xia & Xiang, Dan & Liu, Zhongchun. (2023). Comorbidity of epilepsy and attention-deficit/hyperactivity disorder: a systematic review and meta-analysis. Journal of Neurology. 270. 1-13. 10.1007/s00415-023-11794-z.

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Meta-analysis Finds Association Between Childhood Febrile Seizures and Subsequent ADHD

Febrile seizure (FS) is a type of childhood seizure accompanied by a fever. It is not caused by infection in the central nervous system or other triggers of acute seizures. It is the most common form of childhood seizure, with an occurrence of 2% to 5% in all infants and children between 6 months and 5 years old. 

Noting that “To the best of our knowledge, no systematic synthesis of literature has assessed the nature and magnitude of the association between FS and ADHD,” a Korean research team performed a systematic search of the medical literature followed by meta-analysis to explore any such association. 

Meta-analysis of twelve studies with a combined total of more than 950,000 persons found that childhood febrile seizures were associated with 90% greater odds of subsequent ADHD. Correcting for publication bias reduced this slightly to 80% greater odds of subsequent ADHD. 

Limiting the meta-analysis to the subset of four studies with over 33,000 participants that adjusted for known confounders strengthened the association. Children who had febrile seizures had greater than 2.6-fold greater odds of subsequently developing ADHD. There was no sign of publication bias, but there was substantial divergence in individual study outcomes (heterogeneity). 

Further limiting the meta-analysis to two studies with a combined 654 participants in which clinical ADHD diagnoses were made by specialists – the gold standard – produced the exact same outcome. In this case, heterogeneity dropped to zero. 

The team concluded, “Overall, our systematic review and meta-analysis has shown a significant positive association between childhood FS and later occurrence of ADHD. Our findings add to the growing body of evidence questioning the notion that childhood FS are universally benign. In addition, the results highlight the need for longitudinal studies to better understand the association between FS and ADHD.”  

August 26, 2025

Meta-analysis Finds Little Evidence in Support of Game-based Digital Interventions for ADHD

ADHD treatment usually involves a combination of medication and behavioral therapy. However, medication can cause side effects, adherence problems, and resistance from patients or caregivers. 

Numerous systematic reviews and meta-analyses have evaluated the effects of non-pharmacological interventions on ADHD. With little research specifically examining game-based interventions for children and adolescents with ADHD or conducting meta-analyses to quantify their treatment effectiveness, a Korean study team performed a systematic search of the peer-reviewed medical literature to do just that.  

The Study: 

To be included, studies had to be randomized controlled trials (RCTs) that involved children and adolescents diagnosed with ADHD. The team excluded RCTs that included participants with psychiatric conditions other than ADHD.  

Eight studies met these standards. Four had a high risk of bias.  

Meta-analysis of four RCTs with a combined total of 481 participants reported no significant improvements in either working memory or inhibition from game-based digital interventions relative to controls. 

Likewise, meta-analysis of three RCTs encompassing 160 children and adolescents found no significant improvement in shifting tasks relative to controls. 

And meta-analysis of two RCTs combining 131 participants reported no significant gains in initiating, planning, organizing, and monitoring abilities, nor in emotional control

The only positive results were from two RCTs with only 90 total participants that indicated some improvement in visuospatial short-term memory and visuospatial working memory.  

There was no indication of effect size, because the team used mean differences instead of standardized mean differences.  

Conclusion:

The team concluded, “The meta-analysis revealed that game-based interventions significantly improved cognitive functions: (a) visuospatial short-term memory … and (b) visuospatial working memory … However, effects on behavioral aspects such as inhibition and monitoring … were not statistically significant, suggesting limited behavioral improvement following the interventions.” 

Simply put, the current evidence does not support the effectiveness of game-based interventions in improving behavioral symptoms of ADHD in children and adolescents. The only positive results were from two studies with a small combined sample size, which does not qualify as a genuine meta-analysis. All the other meta-analyses performed with larger sample sizes reported no benefits. 

Understanding Teen Health and Well-being in ADHD: A Fresh Perspective from the CDC

Recent research from the Centers for Disease Control and Prevention (CDC) highlights distinct health and social-emotional challenges faced by teens diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). This study, published in the Journal of Developmental and Behavioral Pediatrics, offers critical insights directly from the teens themselves, providing a unique view often missed when relying solely on parent or clinical reports. 

Researchers analyzed nationally representative data from July 2021 through December 2022, comparing self-reported experiences of teens aged 12 to 17 with and without ADHD. Approximately 10% of teenagers had an ADHD diagnosis, and the findings reveal specific areas where teens with ADHD face notable difficulties. 

Teenagers with ADHD reported significantly higher rates of bullying victimization and struggles in making friends compared to their peers. Surprisingly, they were less likely to report a lack of peer support, suggesting complexities in how they perceive friendships and social networks. The study underscores the importance of directly engaging teens in assessing their social relationships, rather than solely relying on parental perspectives. 

Sleep difficulties emerged as another critical issue for teens with ADHD. About 80% reported problems like difficulty waking up and irregular wake times, markedly higher than their non-ADHD counterparts. Such disruptions can exacerbate attention difficulties and emotional regulation issues, further complicating daily life for these teens. 

Excessive screen time also stood out, with nearly two-thirds of teens with ADHD spending over four hours daily on screens, excluding schoolwork. This high screen usage is concerning, given its potential negative impact on physical and mental health, including sleep quality and social interactions. 

Notably, the study found no significant differences in physical activity levels or concerns about weight between teens with and without ADHD. This finding contrasts with previous studies that have highlighted lower physical activity among children with ADHD, suggesting the need for continued research on how physical activity is measured and encouraged in this population. 

The study’s authors emphasize the importance of health promotion interventions tailored specifically for teens with ADHD. By directly engaging teens and considering their unique perspectives, interventions can better address social-emotional well-being and healthy lifestyle behaviors, ultimately improving long-term outcomes for this vulnerable group. 

Overall, this research provides compelling evidence for healthcare providers, educators, and families to focus on supporting teens with ADHD in areas of social skills, sleep hygiene, and healthy screen time habits. Such targeted support can significantly enhance the quality of life and health outcomes for adolescents navigating the challenges of ADHD.