Study Finds That ADHD Stimulants Have Negligible Effect on Adult Height

Background:

One of the more persistent concerns among parents of children with ADHD is whether stimulant medications will stunt their child's growth. A large Israeli cohort study now offers some of the most rigorous reassurance to date, and its methodology sets it apart from earlier research. 

The question has long been complicated by a more fundamental uncertainty: do growth differences in children with ADHD stem from the condition itself, from stimulant treatment, or from factors present before any medication is ever prescribed? Without a clear answer, clinicians and families have faced a genuine dilemma when weighing the benefits of stimulant therapy against potential long-term physical costs. 

Most previous studies compounded this difficulty by comparing group-average heights, which ignores the crucial variable of genetic potential. A child who is short relative to the general population may simply have short parents. Failing to account for this introduces systematic bias and can make medications appear more harmful than they are. 

The Study:

The Israeli research team addressed this directly. Using health records from a nationwide provider, they assembled a retrospective cohort of children born between 1995 and 2003, following them through 2023. This amount of time was long enough for all participants to have reached adult stature (defined as 17 or older for females, 19 or older for males). Their sample included 5,671 children with untreated ADHD, 11,846 who received stimulant treatment, and 47,258 non-ADHD controls. Children who took stimulants for only one to two months, or who had chronic medical conditions requiring long-term medication, were excluded to avoid confounding the results. 

Crucially, adult height was evaluated not against population norms but against each individual's expected height, calculated from parental heights using the Tanner-Goldstein-Whitehouse method, a standard approach for estimating genetic height potential via mid-parental height. 

When the researchers compared adult heights across the three groups using analysis of variance (ANOVA), they did find statistically significant differences. But statistical significance, particularly in studies with tens of thousands of participants, does not automatically translate into clinical significance. The effect sizes were consistently very small, and the absolute differences were under one centimeter, which is a margin considered clinically negligible. 

Their conclusion is measured but clear: after accounting for genetic growth potential, neither an ADHD diagnosis nor stimulant treatment was associated with meaningful reductions in adult height. The findings, they argue, support prioritizing behavioral and functional outcomes when making treatment decisions, since the risk of clinically significant height loss appears to be minimal. 

The Take-Away:

For families navigating ADHD treatment, the practical implication is significant: concerns about permanent growth suppression, while understandable, should not be the primary driver of whether or how long a child receives stimulant therapy. 

Michal Gabbay, Uri Gabbay, and Doron Carmi, “The impact of ADHD and neurostimulant treatment on normalized height deviance after accounting for genetic height potential,” Pediatric Research (2026), published online, https://doi.org/10.1038/s41390-026-04929-1

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ADHD medication and risk of suicide

ADHD Medication and Risk of Suicide

A Chinese research team performed two types of meta-analyses to compare the risk of suicide for ADHD patients taking ADHD medication as opposed to those not taking medication.

The first type of meta-analysis combined six large population studies with a total of over 4.7 million participants. These were located on three continents - Europe, Asia, and North America - and more specifically Sweden, England, Taiwan, and the United States.

The risk of suicide among those taking medication was found to be about a quarter less than for unmediated individuals, though the results were barely significant at the 95 percent confidence level (p = 0.49, just a sliver below the p = 0.5 cutoff point). There were no significant differences between males and females, except that looking only at males or females reduced sample size and made results non-significant.

Differentiating between patients receiving stimulant and non-stimulant medications produced divergent outcomes. A meta-analysis of four population studies covering almost 900,000 individuals found stimulant medications to be associated with a 28 percent reduced risk of suicide. On the other hand, a meta-analysis of three studies with over 62,000 individuals found no significant difference in suicide risk for non-stimulant medications. The benefit, therefore, seems limited to stimulant medication.

The second type of meta-analysis combined three within-individual studies with over 3.9 million persons in the United States, China, and Sweden. The risk of suicide among those taking medication was found to be almost a third less than for unmediated individuals, though the results were again barely significant at the 95 percent confidence level (p =0.49, just a sliver below the p = 0.5 cutoff point). Once again, there were no significant differences between males and females, except that looking only at males or females reduced the sample size and made results non-significant.

Differentiating between patients receiving stimulant and non-stimulant medications once again produced divergent outcomes. Meta-analysis of the same three studies found a 25 percent reduced risk of suicide among those taking stimulant medications. But as in the population studies, a meta-analysis of two studies with over 3.9 million persons found no reduction in risk among those taking non-stimulant medications.

A further meta-analysis of two studies with 3.9 million persons found no reduction in suicide risk among persons taking ADHD medications for 90 days or less, "revealing the importance of duration and adherence to medication in all individuals prescribed stimulants for ADHD."

The authors concluded, "exposure to non-stimulants is not associated with a higher risk of suicide attempts. However, a lower risk of suicide attempts was observed for stimulant drugs. However, the results must be interpreted with caution due to the evidence of heterogeneity ..."

December 13, 2021

Unmedicated Adult ADHD Linked to Dementia in Population Study

Background:

Noting that “the association between adult ADHD and dementia risk remains a topic of interest because of inconsistent results,” an Israeli study team tracked 109,218 members of a nonprofit Israeli health maintenance organization born between 1933 and 1952 who entered the cohort on January 1, 2003, without an ADHD or dementia diagnosis and were followed up to February 28, 2020. 

Israeli law forbids nonprofit HMOs from turning anyone away based on demographic factors,  health conditions, or medication needs, thereby limiting sample selection bias.  

The estimated prevalence of dementia in this HMO, as diagnosed by geriatricians, neurologists, or psychiatrists, is 6.6%. This closely matches estimates in Western Europe (6.9%) and the United States (6.5%). 

Method:

The team considered, and adjusted for, numerous covariates: age, sex, socioeconomic status, smoking, depression, obesity, chronic obstructive pulmonary disease, hypertension, atrial fibrillation, heart failure, ischemic heart disease, cerebrovascular disease, diabetes, Parkinson’s disease, traumatic brain injury, migraine, mild cognitive impairment, psychostimulants. 

With these adjustments, individuals diagnosed with ADHD were almost three times as likely to be subsequently diagnosed with dementia as those without ADHD. Men with ADHD were two and a half times more likely to be diagnosed with dementia, whereas women with ADHD were over three times more likely, than non-ADHD peers. 

More concerning still, persons with ADHD were 5.5 times more likely to be subsequently diagnosed with early onset dementia, as opposed to 2.4 times more likely to be diagnosed with late onset dementia. 

On the other hand, the team found no significant difference in rates of dementia between individuals with ADHD who were being treated with stimulant medications and individuals without ADHD. Those with untreated ADHD had three times the rate of dementia. The team nevertheless cautioned, “Due to the underdiagnosis of dementia as well as bidirectional misdiagnosis, this association requires further study before causal inference is plausible.” 

Conclusions and Relevance:

This study reinforces existing evidence that adult ADHD is associated with an increased risk of dementia. Notably, the increased risk was not observed in individuals receiving psychostimulant medication, however the mechanism behind this association is not clear.

These findings underscore the importance of reliable ADHD assessment and management in adulthood. They also highlight the need for further study into the link between stimulant medications and the decreased risk of dementia.

 

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February 25, 2025

Meta-analysis Finds Quality of Life Improvements Associated with ADHD Medications

Quality of life (QoL) is defined as a person’s satisfaction with their life, measured across several dimensions including psychological, social, health, biological, and economic well-being. For adults, these are usually self-reported. QoL for children and adolescents is usually reported by parents.  

Medications for ADHD include stimulants (methylphenidate and amphetamines) and non-stimulants (e.g., atomoxetine, clonidine, guanfacine, viloxazine). As QoL is related to ADHD symptoms’ severity, management of ADHD via medication could improve not only core symptoms but also QoL in people with ADHD.  

Noting the absence of meta-analytic evidence on the effects of ADHD medications on QoL, an international research team conducted a systematic review and meta-analysis of parallel or cross-over randomized clinical trials (RCTs) to estimate the effects of ADHD medication on QoL. They also performed secondary analyses to see if these effects differed in children and adolescents versus adults, as well as by class of medications, and if they were moderated by length of treatment. 

Meta-analyses of four RCTs with a combined total of 950 participants with ADHD (45% adults) found a medium effect size improvement among those receiving amphetamines by comparison with those receiving placebo. There was no sign of publication bias, but there was wide variation (heterogeneity) in effect size estimated among the studies.  

Meta-analysis of four RCTs with a combined total of 1,094 participants with ADHD (57% adults) found a small-to-medium effect size improvement among those receiving methylphenidate by comparison with those receiving placebo. Again, there was no sign of publication bias, but wide variation in effect sizes among the studies. 

Due to lack of sufficient data, the team could not explore whether length of treatment affected the results, or if there were differences between children/adolescents and adults. 

Finally, a meta-analysis of eleven RCTs with a combined total of 3,344 participants with ADHD (63% adults) likewise found a small effect size improvement among those taking atomoxetine compared with those receiving placebo. Once again, there was no sign of publication bias, but wide variation in effect sizes among the studies. 

The team was able to establish that for atomoxetine treatment, length of intervention – the studies ranged from 6 to 24 weeks – had no significant moderating effect. Similarly, they found no significant differences in effect on children and adolescents versus adults.  

A single RCT evaluating modafinil treatment in adults found no improvements at any dose, whereas a single RCT testing non-stimulant guanfacine reported a medium effect size improvement in QoL.  Modafinil is not FDA approved for ADHD but is sometimes used as a last resort if other treatments fail.

The team concluded that the FDA approved medications for ADHD were significantly more efficacious than placebo in improving QoL in people with ADHD.  The improvements in Q0L were, however, smaller than what has been found for improvements is the symptoms of ADHD (inattention, hyperactivity, impulsivity).  More work is needed to detect differences by age and length of treatment. 

August 12, 2024

ADHD and Health: How Sex Differences Impact Physical Health into Adulthood

Girls are diagnosed with ADHD at less than half the rate of boys, but this gap closes significantly by adulthood. ADHD also looks different in females than in males, with distinct patterns in symptoms, development, functional impairment, economic impact, and long-term outcomes. Despite this, sex differences in how ADHD relates to physical health have been poorly studied. 

Prior research has established that both children and adults with ADHD face elevated risk for a range of physical health conditions. But that work has been hampered by small samples, retrospective designs, and limited population coverage. 

The Study

Denmark's single-payer national health system makes it possible to conduct truly population-wide research. This study drew on Danish national registers to follow more than 825,000 individuals, born between 1984 and 1995, from birth through adolescence and into young adulthood, tracking them across 13 categories of physical disease. Only individuals free of a relevant physical diagnosis at birth were included, and ADHD diagnosis was treated as something that could be acquired over time rather than a fixed characteristic. 

The Results: 

Across both sexes, people diagnosed with ADHD consistently showed higher disease risk than the general population, with cancer being the one notable exception. The absence of a meaningful cancer signal is expected, given that cancer predominantly affects older age groups than those captured in this study. 

For most other disease categories (including infectious, endocrine, metabolic, respiratory, digestive, musculoskeletal, and genitourinary diseases), elevated risk emerged in early adolescence. For the remaining categories, elevated risk was present at all ages studied. 

The magnitude of these risks was often substantial: 

  • Infectious diseases: Males aged 14–23 with ADHD faced about 20% greater risk than peers without ADHD; females in the same age group faced roughly 80% greater risk. These differences converged to around 45% above baseline beyond that age. 
  • Eye diseases: Before age 11, males with ADHD had more than twice the risk of their non-ADHD peers; females had more than five times the risk. By age 22, both sexes converged at roughly 35% above baseline. 
  • Ear diseases: Risk was more than five times higher in children with ADHD under age 7. 
  • Nervous system diseases: Risk more than doubled across all ages studied. 
  • Endocrine, nutritional, and metabolic diseases: Risk more than doubled between ages 7 and 23. 
  • Skin conditions: Risk more than doubled through age 11. 

By early adulthood, individuals with ADHD showed at least 20% greater risk across every disease category except cancer, regardless of sex. 

Sex Differences Shift With Age 

One of the study's more nuanced findings concerns how sex interacts with ADHD diagnosis over time. In the general population, females tend to have higher physical disease risk from the teenage years onward, while males show higher risk in early childhood. ADHD diagnosis disrupted these patterns unevenly, amplifying risk in some groups and age windows more than others. 

Perhaps most notably, the transition into young adulthood appeared to reduce the ADHD-associated gap between the sexes for endocrine, nutritional, and metabolic diseases (from a ninefold female-to-male disparity down to roughly 4.5-fold). The authors suggest this may reflect ADHD's influence on sex hormone activity during this developmental period. 

Takeaway 

This large, population-representative study confirms that an ADHD diagnosis is associated with meaningfully elevated risk across nearly all categories of physical disease, and that this relationship is neither uniform across sexes nor static across the lifespan. The findings underscore the need for sex-sensitive, developmentally informed approaches to the physical healthcare of people with ADHD. 

Antidepressants in Pregnancy and ADHD Risk: What a Major New Analysis Found

Antidepressants are the primary drug treatment for depressive disorders, which affect 15–20% of pregnant women. They are among the most widely prescribed medications worldwide, and their use has increased in recent decades. Understanding their reproductive safety is critical to support informed, evidence-based prescribing during pregnancy. 

A new meta-analysis sheds important light on one of the most debated concerns: whether children born to mothers who took antidepressants during pregnancy face a higher risk of ADHD. 

The Study: 

Pooling 14 studies covering more than 14 million participants, the analysis found that prenatal antidepressant exposure was associated with a 35% higher rate of ADHD in offspring compared to no exposure. A separate look at SSRIs (the most widely prescribed class of antidepressants, including Prozac and Zoloft) across 11 studies and over four million pregnancies found an even higher apparent risk (44%)  after correcting for publication bias. On the surface, these are striking numbers. 

Both associations came with an important caveat: enormous variation between individual studies, a statistical red flag suggesting the results may not reflect a true underlying effect. More tellingly, the apparent risk evaporated entirely when researchers applied a more rigorous method — comparing siblings within the same family, where one child was exposed to antidepressants in the womb, and another was not. 

This sibling-comparison design is particularly powerful because it automatically controls for factors that run in families: shared genes, household environment, parenting, and socioeconomic conditions. When those influences are held constant, the link between antidepressant exposure and ADHD disappears. The same pattern held for SSRIs specifically. 

Two other antidepressant classes, SNRIs (serotonin norepinephrine reuptake inhibitors) and tricyclics, showed no significant association in any analysis. 

“Confounding by Indication”: 

The probable driver of the initial association is what researchers call confounding by indication. The very condition being treated (depression) is itself a risk factor for ADHD in offspring, independently of any medication. Mothers with more severe depression are also more likely to be prescribed antidepressants, meaning the drug and the underlying illness are difficult to disentangle in standard analyses. Sibling studies cut through this problem cleanly. 

The Take-Away: 

The authors concluded that the association between antidepressants and ADHD risk was non-significant across all analyses designed to account for these confounding factors. This doesn’t mean antidepressants are without any reproductive considerations, but it does suggest that ADHD risk, at least, is driven by heritable and family-level factors rather than medication exposure itself. 

For clinicians and patients weighing the risks of treating or not treating depression during pregnancy, this distinction matters considerably. 

Computerized Cognitive Remediation Therapy for ADHD: A Meta-analysis

Executive functions are the mental processes that allow us to plan, adapt, and follow through. This encompasses working memory, inhibitory control, cognitive flexibility, goal-directed planning, and problem-solving. In people with ADHD, weaknesses in these areas compound the disorder's core symptoms, making it substantially harder to manage complex, real-world demands. 

Background:

Medication remains the frontline clinical response. Stimulant medications can meaningfully reduce both executive function deficits and ADHD symptoms, and are often combined with behavioral or psychological therapies for better overall outcomes.  

Medication, however, is not entirely without risk of side effects. These risks have spurred interest in new, non-pharmacological alternatives that target the same neural pathways. One of these new therapies is Computerized Cognitive Remediation Therapy (CCRT). This therapy uses digital programs delivered via computer, tablet, or smartphone that train attention, memory, and inhibitory control through structured cognitive exercises. A key feature of many CCRT platforms is adaptive difficulty: tasks adjust in real time to match the child’s current ability, keeping training both challenging and engaging. 

The Study: 

Despite this promise, the evidence base in younger populations has been limited. This meta-analysis pooled results from randomized controlled trials enrolling participants under 18 who either carried an ADHD diagnosis or scored above the threshold on a validated rating scale. Comparators included no treatment (waitlist), placebo (pharmacological or psychological), or treatment as usual. The primary outcomes (overall executive function and clinical symptom severity) were assessed via questionnaires and neuropsychological testing. Studies including participants with comorbid autism, tic disorders, epilepsy, or other psychiatric conditions were excluded. 

The findings were informative, but overall results were mixed. CCRT produced a small but statistically meaningful reduction in inattention symptoms across 13 studies (885 participants), with consistent results across individual trials and no evidence of publication bias. However, it had no detectable effect on hyperactivity and impulsivity (12 studies, 833 participants) or on total ADHD symptom burden (10 studies, 731 participants). 

The picture was more encouraging for executive function. Nine studies (500 participants) showed small overall improvements, with specific gains in working memory (454 participants), inhibitory control (428 participants), and planning (6 studies, 335 participants). Emotional control showed no significant change (5 studies, 265 participants), nor did cognitive flexibility (4 studies, 189 participants). 

The Take-Away: 

Taken together, these results are modest rather than transformative, but context matters. CCRT is low-cost, digitally scalable, and carries negligible side effects. For a population where medication often comes with a significant burden of adverse reactions, even small, reliable improvements in executive function represent a meaningful clinical option. 

The evidence positions CCRT not as a replacement for established treatments, but as a practical and well-tolerated addition to the therapeutic toolkit for children and adolescents with ADHD. 

August 5, 2026