October 21, 2025

Meta-analysis Suggests Motor Competence Deficits Associated with ADHD, But With Methodological Shortcomings

Children and adolescents with ADHD tend to be less active and more sedentary than their typically developing peers. This is concerning, since physical activity benefits mental, physical, and social development. For youth with ADHD, being active can improve symptoms like inattention, working memory, and inhibitory control. 

A major barrier to physical activity for children and adolescents with ADHD is limited motor competence. This stems from challenges in developing basic motor skills and more complex abilities needed for sports and advanced movements. 

Difficulties in developing fundamental movement skills – such as locomotor (running, jumping), object-control (throwing, catching), and stability skills (balancing, turning) – can reduce motor competence and limit physical activity. These basic movements are learned and refined with practice and age, not innate abilities. 

To date, research on the link between ADHD and motor competence has remained inconclusive. This systematic review and meta-analysis by a Spanish research team therefore aimed to determine whether children and adolescents with ADHD differ in motor competence from those with typical development (TD). 

Studies had to include children and adolescents diagnosed with ADHD. They had to involve a full motor assessment battery, not just one test, and present motor competence data for both ADHD and TD groups. 

The team excluded studies involving participants with other neurodevelopmental disorders or cognitive impairments, unless separate data for the ADHD subgroup were reported. 

Meta-analysis of six studies combining 323 children and adolescents found that typically developing individuals were twelve times more likely to score in the 5th percentile of the Movement Assessment Battery for Children as their peers diagnosed with ADHD. They were also three times more likely to score in the 15th percentile (five studies, 289 participants). Results were consistent across the studies (low heterogeneity). All included studies were randomized. 

Meta-analysis of five studies totaling 198 participants using the Test of Gross Motor Development reported significant deficits in both locomotor skills and object control skills among children and adolescents diagnosed with ADHD relative to their typically developing peers. In this case, however, results were inconsistent across studies (very high heterogeneity), and one of the studies was unrandomized. Because the team published only unstandardized mean differences, there was no indication of effect sizes. 

Meta-analysis of two studies encompassing 164 participants using the Bruininks-Oseretsky Test of Motor Proficiency similarly yielded significant deficits among children and adolescents diagnosed with ADHD relative to their typically developing peers, but in this case with low heterogeneity. Notably, one of the two studies was not randomized. 

Moreover, the team made no assessment of publication bias. 

The team concluded, “The findings of this review indicate that children and adolescents with ADHD show significantly lower levels of motor competence compared to their TD peers. This trend was evident across a range of validated assessment tools, including the MABC, BOT, TGMD, and other standardized test batteries. Future research should aim to reduce methodological heterogeneity and further investigate the influence of factors such as ADHD subtypes and comorbid conditions on motor development trajectories.” 

However, without a publication bias assessment, reliance on unrandomized studies in two of the tests, no indication of effect size in the same two tests, and small sample sizes, these results are at best suggestive, and will require further research to confirm. 

Nerea Blanco-Martínez, Daniel González-Devesa, Carlos Ayán-Pérez, and José Carlos Diz-Gómez, “Differences in Motor Competence Between Children and Adolescents With and Without ADHD: Findings from a Systematic Review and Meta-analysis,” Journal of Autism and Developmental Disorders (2025), https://doi.org/10.1007/s10803-025-07033-1

Related posts

Meta-analysis finds limited benefits from computerized cognitive training

Meta-analysis Finds Limited Benefits from Computerized Cognitive Training

Computerized cognitive training (CCT) uses computers to try to strengthen cognitive skills and processes, reduce ADHD symptoms, and improve executive functioning. Executive functions are cognitive processes and mental skills that help individuals plan, monitor, and successfully execute their goals.

CCT programs target one or more cognitive processes such as motor inhibition, interference inhibition, sustained attention, and working memory. They ramp up task difficulty as performance improves. The goal is to harness the brain’s inherent adaptability (neuroplasticity) to boost performance. 

A European study team that previously probed the efficacy of CCT through meta-analysis had been unable to provide a robust estimate of effect size due to an insufficient number of high-quality trials with probably blinded outcomes. Noting that “there have been a considerable number of new RCTs [randomized controlled trials] published, many with larger samples, well-controlled designs and blinded outcomes,” the team performed an updated systematic review and meta-analysis.

They included RCTs with participants of any age who either had a clinical diagnosis of ADHD or were above cut-off on validated ADHD rating scales. RCTs had to have been peer-reviewed and published in an academic journal, and to have reported a validated outcome measure of ADHD symptoms, neuropsychological processes, and/or academic outcomes.

Fourteen RCTs with a combined total of 631 participants had probably blinded outcomes. Meta-analysis of these studies yielded no significant effect on either overall ADHD symptoms or hyperactivity/impulsivity symptoms. There was a marginally significant reduction in inattention symptoms, but the effect size was small. Between-study variation (heterogeneity) was negligible and there was no sign of publication bias.

Regarding academic outcomes, meta-analyses revealed no gain in arithmetic ability or reading fluency. There was a small but not statistically significant improvement in reading comprehension. Heterogeneity was minimal, with no indication of publication bias.

With two related exceptions, meta-analyses of RCTs measuring executive functions likewise reported no significant improvements in attention, interference inhibition (initial stage in controlling impulsive behavior), motor inhibition (follow-up stage in controlling impulsive behavior), non-verbal reasoning, processing speed, and set shifting (the ability to unconsciously shift attention between one task and another).

The exceptions were for working memory tasks. Meta-analysis of 15 RCTs with a combined 753 participants reported a highly significant small-to-medium effect size improvement in verbal working memory. A separate meta-analysis of nine RCTs with a total of 441 participants similarly reported a highly significant improvement in visuospatial working memory, this time with medium effect size.

The team concluded, “There was no empirical support for the use of CCT as a stand-alone intervention for ADHD symptoms based on the largest and most comprehensive meta-analysis of RCTs conducted to date. Small effects, of likely limited clinical importance, on inattention symptoms were found – but these were limited to the setting in which the intervention was delivered. Robust evidence of small- to-moderate improvements in visual-spatial and verbal STM/WM tasks did not transfer to other domains of executive functions or academic outcomes.”

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. 

Meta-analysis Finds Narrative Language Impairment in Youths with ADHD

Meta-analysis Finds Narrative Language Impairment in Youths with ADHD

Youths with ADHD are known to be more prone to language problems when compared with typically developing peers. To what extent does that affect their ability to share a narrative with others?

A Danish research team conducted a systematic review and meta-analysis of the peer-reviewed medical literature to explore this question. They stressed that this ability is important because "a narrative is a genre of discourse - a form of social communication used to derive meaning from experiences and to construct a shared understanding of events. In other words, it is the fundamental ability of orally producing a coherent story." They focused on the production of narratives rather than comprehension.

Studies had to have a minimum of 10 participants. They had to compare aspects of oral narrative production in children and adolescents with either a formal ADHD diagnosis or a score above a clinical cut-off on a validated ADHD rating scale to a control group of typically developing youths. Youths with confirmed autism spectrum disorder (ASD) or language impairment diagnoses were excluded. There were no constraints on IQ.

The team found sixteen studies with a combined total of 1,015 youths that met these criteria and were suitable for meta-analysis.

They examined seven aspects of oral narrative production:

·        Coherence: A story structure that is logical and easy to follow in cause and sequence. There is a clear beginning, middle, and end. There are goals, attempts, and outcomes. A meta-analysis of nine studies with a combined total of 750 participants found youths with ADHD less coherent than their typically developing peers, with a medium effect size. There was virtually no between-study heterogeneity and no sign of publication bias.
·        Cohesion: This ensures referencing of events and characters in a manner that enables the listener to grasp how characters, events, and ideas in a story are related. Ambiguous or contradictory references get in the way of this. A meta-analysis of eight studies with a combined total of 501 participants found youths with ADHD showed less cohesion than their typically developing peers, with a medium effect size. Again, with virtually no between-study heterogeneity, and no sign of publication bias.
·        Disruptions: These can be sequence errors, misinterpretations, embellishments, or confabulations - fabricating imaginary experiences as compensation for loss of memory. A meta-analysis of six studies with 389 participants found youths with ADHD had more disruptions than their typically developing peers, with a small-to-medium effect size. There was virtually no between-study heterogeneity and no sign of publication bias.
·        Fluency: Best explained in terms of errors that interfere with this quality, such as false starts, repeating words or sentences, and abandoning sentences without completing them. A meta-analysis of four studies with 220 participants found no difference in fluency between youths with ADHD and their typically developing peers.
·        Production: This is a measure of output -overall length of the story, number of sentences, number of words. After adjusting for evidence of publication bias, a meta-analysis of twelve studies with 645 participants found no difference here.
·        Syntactic complexity: This includes the extent of vocabulary and the use of proper grammar. A meta-analysis of six studies with 272 participants found youths with ADHD displayed less syntactic complexity than their typically developing peers, with a small-to-medium effect size. There was virtually no between-study heterogeneity and no sign of publication bi
·        Internal state language: References to perceptions, thoughts, beliefs, and feelings. There were only two studies with 130 participants, so no meta-analysis was performed.

The authors concluded, "the results from the current meta-analysis suggest that children with ADHD have impairments in their narrative language. In particular, children with ADHD produce narratives that are less coherent, less cohesive, less syntactically complex, and include more disruptive errors than typically developing children do."

December 4, 2023

Large Cohort Study Reports Association Between Eye Disorders and ADHD

Refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (distorted vision due to irregular curvature of the eye or lens), are common worldwide. These conditions affect 12%, 5%, and 15% of children, and rise significantly in adults to 26.5%, 31%, and 40%. Additionally, strabismus (misalignment of the eyes) and amblyopia (reduced vision in one eye from uneven image formation, often linked to strabismus) occur globally at rates of 2% and 1.4%, respectively. 

Visual impairment can affect children’s concentration in school, and studies suggest a link between eye disorders and ADHD. 

To investigate this relationship, two researchers – one based in the US and the other in Israel –carried out a nationwide retrospective cohort study using electronic medical records of all insured individuals aged 5 to 30 who were part of Maccabi Health Services, Israel’s second largest health maintenance organization, between 2010 and 2022. 

Of over 1.6 million insured members (2010–2020), inclusion/exclusion criteria and propensity score matching for age and sex were applied, along with a one-year wash-out period between the first eye diagnosis and ADHD diagnosis. In total, 221,707 cases were matched with controls without eye disorders at a 1:2 ratio, resulting in a cohort of 665,121 participants.  

Overall, those with any previous eye diagnosis were 40% more likely to have a subsequent ADHD diagnosis. This was slightly higher for females (45%) than for males (35%). It was also slightly higher for children and adolescents (42%) than for adults (37%).  

More specifically: 

  • Myopia (425,000+ participants): 30% higher ADHD rate. 
  • Hyperopia (120,000+) and astigmatism (175,000+): over 50% higher ADHD rate. 
  • Strabismus (13,000+): over 60% higher ADHD rate. 
  • Amblyopia (14,000+): 40% higher ADHD rate. 

The authors concluded that eye disorders are associated with ADHD. They noted these associations were more marked in females and children and adolescents, although, as noted above, those differences were small. They recommended that primary care providers and neurologists consider risk stratification for early screening, and that ophthalmologists refer high-risk patients for ADHD evaluation. 

 

 

February 10, 2026

South Korean Nationwide Population Study: Prenatal Exposure to Acid-suppressive Medications Not Linked to Subsequent ADHD

Acid-suppressive medications, including proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists, are often prescribed during pregnancy to treat heartburn and gastroesophageal reflux disease. 

Research shows changes in the gut microbiome can negatively affect neurodevelopment. Since acid-suppressive medications alter gut microbiota, maternal use during pregnancy may impact offspring’s neurodevelopment. Because PPIs and H2 receptor antagonists readily cross the placental barrier, they could potentially influence fetal neurodevelopment.  

The link between prenatal exposure to acid-suppressive medications and major neuropsychiatric disorders is not well understood. With the use of these medications during pregnancy rising, it is important to assess their impact on children's long-term neurodevelopment. This study examined whether maternal use of acid-suppressive drugs is associated with increased risk of neuropsychiatric disorders in children, using a large, nationwide birth cohort from South Korea. 

South Korea operates a single-payer health insurance system, providing coverage for over 97% of its citizens. The National Health Insurance Service (NHIS) maintains a comprehensive database with sociodemographic details, medical diagnoses, procedures, prescriptions, health examinations, and vital statistics for all insured individuals. 

A Korean research team analyzed data from over three million mother-child pairs (2010–2017) to assess the risks of prenatal exposure to acid-suppressing medications. They applied propensity scoring to adjust for maternal age, number of children, medical history, and outpatient visits before pregnancy, to minimize confounding factors. That narrowed the cohort to just over 800,000 pairs, with half in the exposed group. 

With these adjustments, prenatal exposure to acid-suppressing medications was associated with 14% greater likelihood of being subsequently diagnosed with ADHD. 

Yet, when 151,737 exposed births were compared to the same number of sibling controls, no association was found between prenatal exposure and subsequent ADHD, which suggests unaccounted familial and genetic factors influenced the preceding results. 

The Take-Away:

Evidence of these medications negatively affecting pregnancies is mixed, mostly observational, and generally reassuring when these medications are used appropriately. Untreated GERD and gastritis, however, have known risks and associations with the development of various cancers. With no evidence of an association with ADHD (or for that matter any other neuropsychiatric disorder), there is no current evidence-based reason for expectant mothers to discontinue use of acid-suppressing medications.  

February 6, 2026

The 'Medication Tolerance' Myth in ADHD: What the Evidence Actually Says

For years, a persistent concern has shadowed the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD): Does the medication eventually stop working? Patients often report that their symptoms seem to return despite consistent use, leading to "dose escalation" or "medication holidays." A new systematic review from Sam Cortese’s team  published in CNS Drugs finally puts these concerns to the test by synthesizing decades of empirical research.

Before diving into the findings, you must understand two often-confused phenomena:

  • Tachyphylaxis (Acute Tolerance): A rapid decrease in response to a drug, often occurring within a single day (24 hours).
  • Tolerance: A gradual reduction in responsiveness over long-term exposure, requiring higher doses to achieve the original effect.

The review analyzed 17 studies covering over 10,000 individuals, and the results provide a much-needed reality check for the clinical community.

The researchers found preliminary evidence that acute tolerance (tachyphylaxis) can occur within a 24-hour window.

  • Subjective Effects: Studies showed that "drug liking" or feelings of euphoria from stimulants often peak and fade faster than the actual drug concentration in the blood.
  • Clinical Impact: This phenomenon is why some older, flat-release formulations were less effective than modern "ascending" delivery systems (like OROS-methylphenidate), which are designed to overcome this daily dip in efficacy.

The most important finding is that tolerance does not commonly develop to the therapeutic effects of ADHD medication in the long term. In one landmark study following children for up to 10 years, only 2.7% of participants lost their response to methylphenidate without a clear external explanation.  Doses, when adjusted for natural body growth, remained remarkably stable over years of treatment.

Consistent with the lack of therapeutic tolerance, the body does not become tolerant to the physical side effects of stimulants.  Increases in heart rate and blood pressure typically persist for as long as the medication is taken.  This underscores why clinicians must continue monitoring cardiovascular health throughout the entire duration of treatment.

If it’s Not Tolerance, What Is It?

If "tolerance" isn't real, why do some patients feel their medication is failing? The review suggests clinicians look at these alternative explanations:

  1. Natural Symptom Fluctuations: ADHD is not a static condition; symptoms naturally wax and wane over time regardless of treatment.
  2. Limited Compliance: Missed doses or inconsistent timing are often the real culprits behind "failing" efficacy.
  3. Life Events & Transitions: New jobs, academic pressures, or stressful life changes can increase the "functional demand" on a patient, making their current dose feel insufficient.
  4. Co-occurring Conditions: The emergence of anxiety, depression, or substance use disorders can mask or mimic a return of ADHD symptoms.

Why This Matters

These results provide clinicians the confidence to tell patients that their medication is unlikely to "wear out" permanently. Rather than immediately increasing a dose when symptoms flare, the first step should be a "clinical deep dive" into the patient's lifestyle, stress levels, and adherence.

For researchers, the review highlights a major gap: most existing studies are small, dated, or of low quality. There is a dire need for robust, longitudinal studies that track both the brain's response and the patient's environment over several years.

For people with ADHD, while your body might get "used to" the initial "buzz" of a stimulant within hours, its ability to help you focus and manage your life remains remarkably durable over the years.