May 16, 2025

Seven New Meta-analyses Suggest Wide Range of Benefits from Exercise for Persons with ADHD

ADHD is associated with deficits in executive functions. These are mental processes that enable individuals to plan, focus attention, manage tasks, and regulate emotions. These skills encompass working memory, cognitive flexibility, and inhibitory control, which are crucial for goal-directed behavior and decision-making. 

Working memory, which temporarily stores and processes information, contributes to language development by helping individuals make sense of what they read or hear.  

Cognitive flexibility refers to the ability to change perspectives, adapt thinking strategies, adjust to changing needs and priorities, recognize errors, and grasp opportunities.  

Inhibition switching involves intentional control of attention and emotions, suppressing automatic responses when necessary to prevent inappropriate behavior.  

These elements are critical to academic, social, and professional success. 

An international study team (Li et al.) conducted a meta-analysis of randomized controlled trials (RCTs) to explore the efficacy of physical activity for improving executive functions among children with ADHD aged 6 to 12. 

Meta-analysis of eleven RCTs encompassing 388 children reported a medium-to-large effect size improvement in cognitive flexibility. However, it found no benefit from aerobic exercise (such as running, jumping). When limited to the nine studies with 301 children that focused on cognitively engaging exercise (such as soccer and water sports that require constant monitoring of other players and strategizing), it found a large effect size improvement. Correcting for possible publication bias had no effect on the outcome. 

Meta-analysis of nine RCTs totaling 398 children reported a large effect size improvement in working memory. Once again, it found no benefit from aerobic exercise. Focusing on the seven RCTs with 288 children that used cognitively engaging exercise, it found a very large effect size improvement. There was no sign of publication bias. 

Meta-analysis of fourteen RCTs combining 579 children reported a small-to-medium effect size improvement in inhibition switching. But whereas it found a medium effect size improvement for shorter interventions of less than an hour (eight RCTs, 334 children), it found no benefit from interventions lasting an hour or more (six RCTs, 245 children. Again, there was no sign of publication bias. 

The team concluded, “Our study shows that physical activity interventions have a positive effect on improving executive function in school-age children with ADHD, with cognitive-engaging exercises showing greater benefits across three executive function measures.” 

A Chinese study team (Yang et al.) performed a related meta-analysis on the effect of exercise on inhibitory control in adults. Combining eight RCTs with a total of 372 participants, it reported a very large effect size improvement in inhibitory control, primarily from regular exercise. However, the effects were heavily influenced by a couple of outliers. The team claimed to have performed a sensitivity analysis but offered no evidence. Likewise, they noted signs of publication bias but did not use the standard trim-and-fill analysis to correct for it. 

Another Chinese study team (Xiangqin Song et al.) examined the effect of exercise on working memory in children and adolescents.  

Meta-analysis of 17 RCTs encompassing 419 participants found a medium effect size improvement in working memory. The large effect size improvement for cognitive aerobic exercise (4 RCTs, 233 participants) was twice the effect size for simple aerobic exercise (8 RCTs, 397 participants), though this meta-analysis still found a small-to-medium effect size gain from the latter. There was no sign of publication bias.  

The team concluded, “The results indicate that cognitive-aerobic exercise and ball sports are significantly more effective than other types of exercise interventions in improving working memory. This difference may be attributed to the varying cognitive load, task complexity, and the degree of activation of executive functions across different exercise types. The findings suggest that when designing exercise interventions for children with ADHD, priority should be given to exercise types with higher cognitive load in order to more effectively enhance working memory.” 

A joint Australian-U.S. team (Singh et al.) conducted a meta-meta-analysis on the effect of exercise on executive functions, that is, a meta-analysis of previous meta-analyses of RCTs.  

Combining ten separate meta-analyses with well over 2,800 children and adolescents with ADHD, it reported large effect size improvements in executive functions overall. There was no further breakdown by type of executive function and type of physical activity.  

The team concluded, “While exercise was seen to have a moderate and similar positive impact across all populations with respect to general cognition and memory, benefits for executive function were particularly marked in individuals with ADHD. This subgroup was unique in demonstrating a large effect size. This could be attributed to the task selection and the fact that many ADHD studies involved children. While the exact reason for this finding is unclear, there is evidence to suggest that impairments in executive function are common among individuals with ADHD. As such, it is plausible that this population may have a greater capacity for improvement due to starting from a lower baseline, compared with those with ‘normal’ executive function.” 

Another Chinese study team (Yagang Song et al.) performed a meta-analysis of RCTs examining the effects of physical exercise on anxiety, depression, and emotion regulation among children and adolescents with ADHD.  

Meta-analysis of eleven studies with a combined total of 384 participants reported a medium effect size reduction in symptoms of anxiety, with a dose-effect response. Physical exercise once a week had no significant effect, while twice a week was associated with a medium effect size reduction, and three or more times a week with a very large effect size improvement. Moderate intensity exercise was three times more effective than low intensity exercise.  

Meta-analysis of seven studies encompassing 187 individuals similarly reported a medium effect size reduction in symptoms of depression. Once again, moderate intensity was far more effective than low intensity exercise. 

Meta-analysis of seven studies totaling 429 children and adolescents reported a very large effect size improvement in emotion regulation, especially for physical exercise conducted at least twice a week

There was no sign of publication bias in the anxiety, depression, or emotion regulation findings. 

The team concluded, “Physical exercise demonstrated a substantial overall impact on enhancing anxiety, depression, and emotional regulation in children with ADHD, exhibiting a dose-response effect correlated with the period, frequency, duration, and intensity of the exercise. This investigation ... presents an additional evidence-based therapeutic approach for the considerable number of children with ADHD who are not appropriate candidates for pharmacological intervention.” 

A joint U.S.-Hong Kong study team (Liu et al.) performed a meta-analysis exploring the effect of physical exercise on motor proficiency. Motor proficiency includes both gross motor skills (like walking and running) and fine motor skills (like writing and buttoning).  

Meta-analysis of ten studies encompassing 413 children and adolescents with ADHD reported a very large effect size improvement in motor proficiency from physical exercise. The gains for object control, fine manual control, and manual coordination were roughly twice the gains for body coordination. There was no sign of publication bias. 

Finally, a Spanish research team (González-Devesa et al.) conducted a meta-analysis examining the effect of exercise on objectively measured sleep status among persons with ADHD. 

Meta-analysis of three RCTs with a combined total of 131 individuals that used accelerometers to measure sleep duration reported no significant effect one way or the other from exercise

The team concluded, “The existing evidence regarding the use of exercise to manage sleep problems in individuals with ADHD remains inconclusive. Preliminary findings from this review suggest a potential positive effect of exercise on self-reported sleep quality; however, its efficacy in improving sleep duration could not be confirmed.” 

The Take-Away:

An ideal exercise regimen for children with ADHD should focus on cognitively engaging physical activities rather than simple aerobic exercise. Sports and activities that require strategic thinking, attention to others’ actions, and rapid decision-making—such as soccer, martial arts, or water-based team sports—gave the best results, especially for working memory and cognitive flexibility. These types of exercise also show strong benefits for emotional regulation, reducing anxiety and depression, and enhancing motor proficiency.

To maximize benefits, the regimen should include moderate-intensity sessions at least two to three times per week, each lasting less than an hour, as longer durations appear less effective for improving inhibitory control. This structured, cognitively demanding approach offers an evidence-based, non-pharmacologic treatment option for children with ADHD, particularly for those who cannot or prefer not to use medication.  We need, however, more work to determine if exercise will provide the same symptom reduction and protection from adverse outcomes as has been shown for medications.

Daniel González-Devesa, Miguel Adriano Sanchez-Lastra, José Carlos Diz-Gómez, and Carlos Ayán-Pérez, “Effectiveness of Exercise on Sleep Quality in Attention Deficit Hyperactivity Disorder: A Systematic Review and Meta-Analysis,” Children (2025) 12, 119, https://doi.org/10.3390/children12020119

Dong Li, Chuyuan Miao, Deng Wang, and Chenmu Li, “Effect of physical activity interventions on executive functions in school-age children with ADHD: A meta-analysis of randomized controlled trials,” Journal of Affective Disorders (2025), https://doi.org/10.1016/j.jad.2025.01.155

Hok Ling Venus Liu, Fenghua Sun, David I. Anderson, and Choi Yeung Andy Tse, “The Effect of Physical Activity Intervention on Motor Proficiency in Children and Adolescents with ADHD: A Systematic Review and Meta-analysis,” Child Psychiatry & Human Development (2025) 56:177–191, https://doi.org/10.1007/s10578-023-01546-5

Ben Singh, Hunter Bennett, Aaron Miatke, Dorothea Dumuid, Rachel Curtis, Ty Ferguson, Jacinta Brinsley, Kimberley Szeto, Jasmine M Petersen, Claire Gough, Emily Eglitis, Catherine EM Simpson, Christina L Ekegren, Ashleigh E Smith, Kirk I Erickson, and Carol Maher, “Effectiveness of exercise for improving cognition, memory and executive function: a systematic umbrella review and meta-meta-analysis,” British Journal of Sports Medicine (2025) 0:1-11, https://doi.org/10.1136/bjsports-2024-108589

Xiangqin Song, Yaoqi Hou, Wenying Shi, Yan Wang, Feifan Fan, and Liu Hong, “Exploring the impact of different types of exercise on working memory in children with ADHD: a network meta-analysis,” Frontiers in Psychology (2025) 16:1522944, https://doi.org/10.3389/fpsyg.2025.1522944

Yagang Song, Shuqi Jia, Xing Wang, Aiwei Wang, Tao Ma, Shufan Li, Jiwei Che, Zhaohui Guo, Feng Ding, Yuxi Ren, and Man Qin, “Effects of physical exercise on anxiety, depression, and emotion regulation in children with attention deficit hyperactivity disorder: a systematic review and meta-analysis,” Frontiers in Pediatrics (2025) Vol. 12, https://doi.org/10.3389/fped.2024.1479615

Yi Yang, Chang-Hong Wu, Liang Sun, Ting-Ran Zhang, and Jiong Luo, “The impact of physical activity on inhibitory control of adult ADHD: a systematic review and meta-analysis,” Journal of Global Health (2025) Vol. 15, 10.7189/jogh.15.04025

 

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Immediate and Long-term Effects of Exercise on ADHD Symptoms and Cognition

Immediate and Longer-term Effects of Exercise on ADHD Symptoms and Cognition

A team of Spanish researchers has published a systematic review of 16 studies with a total of 728 participants exploring the effects of physical exercise on children and adolescents with ADHD. Fourteen studies were judged to be of high quality, and two of medium quality.

Seven studies looked at the acute effects of exercise on eight to twelve-year-old youths with ADHD. Acute means that the effects were measured immediately after periods of exercise lasting up to 30 minutes. Five studies used treadmills and two used stationary bicycles, for periods of five to 30 minutes. Three studies "showed a significant increase in the speed of reaction and precision of response after an intervention of 20-30 min, but at moderate intensity (50-75%)." Another study, however, found no improvement in mathematical problem-solving after 25 minutes using a stationary bicycle at low (40-50%) or moderate intensity (65-75%). The three others found improvements in executive functioning, planning, and organization in children after 20- to 30-minute exercise sessions.

Nine studies examined longer-term effects, following regular exercise over many weeks. One reported that twenty consecutive weekly yoga sessions improved attention. Another found that moderate to vigorous physical activity (MVPA) led to improved behavior beginning in the third week, and improved motor, emotional and attentional control, by the end of five weeks. A third study reported that eight weeks of starting the school day with 30 minutes of physical activity led to improvement in Connor's ADHD scores, oppositional scores, and response inhibition. Another study found that twelve weeks of aerobic activity led to declines in bad mood and inattention. Yet another reported that thrice-weekly 45-minute sessions of MVPA over ten weeks improved not only muscle strength and motor skills, but also attention, response inhibition, and information processing.

Two seventy-minute table tennis per week over twelve weeks improved executive functioning and planning, in addition to locomotor and object control skills.

Two studies found a significant increase in brain activity. One involved two hour-long sessions of rowing per week for eight weeks, the other three 90-minute land-based sessions per week for six weeks. Both studies measured higher activation of the right frontal and right temporal lobes in children, and lower theta/alpha ratios in male adolescents.

All 16 studies found positive effects on cognition. Five of the nine longer-term studies found positive effects on behavior. No study found any negative effects. The authors of the review concluded that physical activity "improves executive functions, increases attention, contributes to greater planning capacity and processing speed and working memory, improves the behavior of students with ADHD in the learning context, and consequently improves academic performance." Although the data are limited by a lack of appropriate controls, they suggest that, in addition to the well-known positive effects of physical activity, one may expect to see improvements in ADHD symptoms and associated features, especially for periods of sustained exercise.

July 18, 2021

How Effective Is Exercise in Treating ADHD?

New meta-analysis explores effectiveness of physical exercise as treatment for ADHD

Noting that "Growing evidence shows that moderate physical activity (PA) can improve psychological health through enhancement of neurotransmitter systems," and "PA may play a physiological role similar to stimulant medications by increasing dopamine and norepinephrine neurotransmitters, thereby alleviating the symptoms of ADHD," a Chinese team of researchers performed a comprehensive search of the peer-reviewed journal literature for studies exploring the effects of physical activity on ADHD symptoms.

They found nine before-after studies with a total of 232 participants, and fourteen two-group control studies with a total of 303 participants, that met the criteria for meta-analysis.

The meta-analysis of before-after studies found moderate reductions in inattention and moderate-to-strong reductions in hyperactivity/impulsivity. It also reported moderate reductions in emotional problems and small-to-moderate reductions in behavioral problems.

The effect was even stronger among unmediated participants. There was a very strong reduction in inattention and a strong reduction in hyperactivity/impulsivity.

The meta-analysis of two-group control studies found strong reductions in inattention, but no effect on hyperactivity/impulsivity. It also found no significant effect on emotional and behavioral problems.

There was no sign of publication bias in any of the meta-analyses.

The authors concluded, "Our results suggest that PA intervention could improve ADHD-related symptoms, especially inattention symptoms. However, due to a lot of confounders, such as age, gender, ADHD subtypes, the lack of rigorous double-blinded randomized-control studies, and the inconsistency of the PA program, our results still need to be interpreted with caution."

February 21, 2022

Myths About the Treatment of ADHD

Myths About The Treatment of ADHD

Myth:  ADHD medications "anesthetize" ADHD children.
 
The idea here is that the drug treatment of ADHD is no more than a chemical straightjacket intended to control a child's behavior to be less bothersome to parents and teachers. After all, everyone knows that if you shoot up a person with tranquilizers, they will calm down.

Fact:  ADHD medications are neither anesthetics nor tranquilizers.

The truth of the matter is that most ADHD medications are stimulants. They don't anesthetize the brain; they stimulate it. By speeding up the transmission of dopamine signals in the brain, ADHD medications improve brain functioning, which in turn leads to an increased ability to pay attention and control behavior.  The non-stimulant medications improve signaling by norepinephrine. They also improve the brain's ability to process signals. They are not sedatives or anesthetics. When taking their medication, ADHD patients can focus and control their behavior to be more effective in school, work, and relationships.  They are not "drugged" into submission.

Myth: ADHD medications cause drug and alcohol abuse
We know from many long-term studies of ADHD children that when they reach adolescence and adulthood, they are at high risk for alcohol and drug use disorders. Because of this fact, some media reports have implied that their drug use was caused by treatment of their ADHD with stimulant medications.

Fact: ADHD medications do not cause drug and alcohol abuse
Some ADHD medications indeed use the same chemicals that are found in street drugs, such as amphetamine.  But there is a very big difference between these medications and street drugs. When street drugs are injected or snorted, they can lead to addiction, but when they are taken in pill form as prescribed by a doctor, they do not cause addiction. When my colleagues and I examined the world literature on this topic, we found that rather than causing drug and alcohol abuse, stimulant medicine protected ADHD children from these problems later in life. One study from researchers at Harvard University and the Massachusetts General Hospital found that the drug treatment of ADHD reduced the risk for illicit drug use by84 a percent. These findings make intuitive sense. These medicines reduce the symptoms of the disorder that lead to illicit drug use. For example, an impulsive ADHD teenager who acts without thinking is much more likely to use drugs than an ADHD teen whose symptoms are controlled by medical drug treatment. After we published our study, other work appeared. Some of these studies did not agree that ADHD medications protected ADHD people from drug abuse, but they did not find that they caused drug abuse.

Myth:  Psychological or behavioral therapies should be tried before medication.  
Many people are cautious about taking medications, and that caution is even stronger when parents consider treatment options for their children.  Because medications can have side effects, shouldn't people with ADHD try to talk therapy before taking medicine?

Fact:  Treatment guidelines suggest that medication is the first-line treatment.
The problem with trying talk or behavior therapy before medication is that medication works much better.  For ADHD adults, one type of talk therapy(cognitive behavioral therapy) is recommended, but only when the patient is also taking medication.  The multimodal treatment of ADHD (MTA) study examined this issue in ADHD children from several academic medical centers in the United States. That study found that treating ADHD with medication was better than treating it with behavior therapy. Importantly, behavior therapy plus medication was no more effective than medication alone. That is why treatment guidelines from the American Academy of Pediatrics and the American Academy of Children and Adolescents recommend medicine as a first-line treatment for ADHD, except for preschool children. ADHD medications indeed have side effects, but these are usually mild and typically do not interfere with treatment.  And don't forget about the risks that a patient faces when they do not use medications for ADHD.  These untreated patients are at risk for worsening ADHD symptoms and complications.

Myth: Brain abnormalities of ADHD patients are caused by psychiatric medications
A large scientific literature shows that ADHD people have subtle problems with the structure and function of their brains.  Scientists believe that these problems are the cause of ADHD symptoms. Critics of ADHD claim that these brain problems are caused by the medications used to treat ADHD.  Who is right?

Fact: Brain abnormalities are found in never medicated ADHD patients.
Alan Zametkin, a scientist at the US National Institute of Mental Health, was the first to show brain abnormalities in ADHD patients who had never been treated for their ADHD.  He found that some parts of the brains of ADHD patients were underactive. His findings could not be due to medication because the patients had never been medicated. Since his study, many other researchers have used neuroimaging to examine the brains of ADHD patients. This work confirmed Dr. Zametkin’s observation of abnormal brain findings in unmediated patients. Reviews of the brain imaging literature have concluded that the brain abnormalities seen in ADHD cannot be attributed to ADHD medications.

May 15, 2021

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.

Population Study Finds Association Between Extended Methylphenidate Use By Children and Subsequent Obesity

South Korean Nationwide Population Study Finds Association Between Extended Methylphenidate Use By Children and Subsequent Obesity–Little to No Effect on Adult Height

South Korean Nationwide Population Study Finds Association Between Extended Methylphenidate Use By Children and Subsequent Obesity–Little to No Effect on Adult Height

The Background:

Concerns remain about how ADHD and methylphenidate (MPH) use might affect children's health and growth, and especially how it may affect their adult height. While some studies suggest disrupted growth and a possible biological mechanism, the impact of ADHD prevalence and MPH use is still unclear. Children with ADHD may develop unhealthy habits – irregular eating, low physical activity, and poor sleep – that can contribute to obesity and reduced height. MPH’s appetite-suppressing effect can lead to skipped meals or overeating. Since growth hormone is mainly released during deep sleep, chronic sleep deprivation could plausibly slow growth and impair height development; however, a clear link between ADHD, MPH use, overweight, and shorter stature has never been firmly established. 

The Study:

South Korea has a single payer health insurance system that covers more than 97% of its population. A Korean research team used the National Health Insurance Service database to perform a nationwide population study to explore this topic further. 

The study involved 34,850 children, of whom 12,866 were diagnosed with ADHD. Of these children, 6,816 (53%) had received methylphenidate treatment, while 6,050 (47%) had not. Each patient with ADHD was precisely matched 1:1 by age, sex, and income level to a control participant without ADHD. The sex ratio was comparable in all groups.The team used Body Mass Index (BMI) as an indicator of overweight and obesity. 

The Results: 

The researchers found that being diagnosed with ADHD was associated with 50% greater odds of being overweight or obese as young adults, and over 70% greater odds of severe obesity (BMI > 30) compared to matched non-ADHD controls, regardless of whether or not they were medicated.

Those diagnosed with ADHD, but not on methylphenidate, had 40% greater odds of being overweight or obese, and over 55% greater odds of becoming severely obese, relative to matched non-ADHD controls. 

Methylphenidate users had 60% greater odds of being overweight or obese, and over 85% greater odds of becoming severely obese, relative to matched non-ADHD controls. 

There were signs of a dose-response effect. Less than a year’s exposure to methylphenidate was associated with roughly 75% greater odds of becoming severely obese, whereas exposure over a year or more raised the odds 2.3-fold, relative to matched non-ADHD controls. Using MPH increased the prevalence of overweight from 43.2% to 46.5%, with a greater prevalence among those using MPH for more than one year (50.5%).

It is important to note that most of this effect was from ADHD itself, with methylphenidate only assuming a predominant role in severe obesity among those with longer-term exposure to the medicine. 

As for height, children with ADHD were no more likely to be short of stature than matched non-ADHD controls. Being prescribed methylphenidate was associated with slightly greater odds (7%) of being short of stature, but there was no dose-response relationship. 

Conclusion: 

The team concluded, “patients with ADHD, particularly those treated with MPH, had a higher BMI and shorter height at adulthood than individuals without ADHD. Although the observed height difference was clinically small in both sexes and age groups, the findings suggest that long-term MPH exposure may be associated with growth and body composition, highlighting the need for regular monitoring of growth.” They also point out that “Despite these findings, the clinical relevance should be interpreted with caution. In our cohort, the mean difference in height was less than 1 cm (eg, maximum −0.6 cm in females) below commonly accepted thresholds for clinical significance.”  Likewise, increases in overweight/BMI were small. 

One problem with interpreting the BMI/obesity results is that some of the genetic variants that cause ADHD also cause obesity.  If that genetic load increases with severity of ADHD than the results from this study are confounded because those with more severe ADHD are more likely to be treated than those with less severe ADHD.

Due to these small effects along with the many study limitations noted by the authors, these results should be considered alongside the well-established benefits of methylphenidate treatment.

February 2, 2026