August 12, 2024

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. 

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Alessio Bellato, Nadia J. Perrott, Lucia Marzulli, Valeria Parlatini, David Coghill, and Samuele Cortese, “Systematic Review and Meta-Analysis: Effects of Pharmacological Treatment for Attention-Deficit/Hyperactivity Disorder on Quality of Life,” Journal of the American Academy of Child & Adolescent Psychiatry (2024), https://doi.org/10.1016/j.jaac.2024.05.023. 

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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

How Effective and Safe are Stimulant Medications for Older Adults?

How effective and safe are stimulant medications for older adults?

Older adults are at greater risk for cardiovascular disease. Psychostimulants may contribute to that risk through side effects, such as elevation of systolic blood pressure, diastolic blood pressure, and heart rate.

On the other hand, smoking, substance abuse, obesity, and chronic sleep loss - all of which are associated with ADHD - are known to increase cardiovascular risk, and stimulant medications are an effective treatment for ADHD.

So how does this all shake out? A Dutch team of researchers sets out to explore this. Using electronic health records, they compared all 139 patients 55 years and older at PsyQ outpatient clinic, Program Adult ADHD, in The Hague. Because a principal aim of the study was to evaluate the effect of medication on cardiovascular functioning after first medication use, the 26 patients who had previously been prescribed ADHD medication were excluded from the study, leaving a sample size of 113.

The ages of participants ranged from 55 from 79, with a mean of 61. Slightly over half were women. At the outset, 13 percent had elevated systolic and/or diastolic blood pressure, 2 percent had an irregular heart rate, 15 percent had an abnormal electrocardiogram, and 29 percent had some combination of these (a "cardiovascular risk profile"), and 21 percent used antihypertensive medication.

Three out of four participants had at least e comorbid disorder. The most common are sleep disorders, affecting a quarter of participants, and unipolar mood disorders (depressive or more rarely manic episodes, but not both), also affecting a quarter of participants.

Twenty-four patients did not initiate pharmacological treatment. Of the 89 who received ADHD medication, 58 (65%) reported positive effects, and five experienced no effect. Thirty-eight (43%) discontinued ADHD medication while at the clinic due to lack of effect or to side effects. The most commonly reported positive effects were enhanced concentration, more overview, less restlessness, more stable mood, and having more energy. The principal reasons for discontinuing medication were anxiety/depression, cardiovascular complaints, and lack of effect.

Methylphenidate raised heart rate and lowered weight, but had no significant effect on systolic and diastolic blood pressure. Moreover, there was no significant correlation between methylphenidate dosage and any of these variables, nor between methylphenidate users taking hypertensive medication and those not taking such medication. There was no significant difference in systolic or diastolic blood pressure and heart rate before and after the use of methylphenidate among patients with the cardiovascular risk profiles.

Systolic blood pressure rose in ten out of 64 patients, with two experiencing an increase of at least 20 mmHg. It descended in five patients, with three having a decrease of at least 20 mmHg. Diastolic blood pressure rose by at least 10 mmHg in four patients, while dropping at least 10 mmHg in five others.

The authors concluded "that the use of a low dose of ADHD-medication is well tolerated and does not cause clinically significant cardiovascular changes among older adults with ADHD, even among those with an increased cardiovascular risk profile. Furthermore, our older patients experienced significant and clinically relevant improvement of their ADHD symptoms using stimulants, comparable with what is found among the younger age group," and that "the use of methylphenidate may be a relatively safe and effective treatment for older adults with ADHD, under the condition that all somatic complaints and especially cardiovascular parameters are monitored before and during pharmacological treatment."

Yet they cautioned that "due to the observational nature of the study and the lack of a control group, no firm conclusions can be drawn as to the effectiveness of the stimulants used. ... Important factors that were not systematically reported were the presence of other risk factors, such as smoking, substance (ab)use, aspirin use, and level of physical activity. In addition, the response to medication was not systematically measured"

December 21, 2021

How do Stimulants Modulate the Brain to Improve ADHD Symptoms?

How do Stimulants Modulate the Brain to Improve ADHD Symptoms?

The stimulants methylphenidate and amphetamine are well known for their efficacy in treating symptoms of ADHD in both youth and adults.   Although these medications have been used for several decades, relatively little is known about the mechanisms of action that lead to their therapeutic effect.    

New data about the mechanism comes from a meta-analysis by Katya Rubia and colleagues. They analyzed 14 functional magnetic resonance imaging (fMRI) data sets comprising 212 youth with ADHD.  Each of these data sets assessed the short-term effects of stimulants on fMRI-assessed brain activations. In the fMRI paradigm, ADHD and control participants are asked to do a neurocognitive task while the activity of their brains is being measured. Dr. Rubia and colleagues analyzed data from fMRI assessments of time discrimination, inhibition, and working memory, each of which is known to be deficient in ADHD patients.    

The meta-analysis found that the most consistent brain activations were seen in a region comprising the right inferior frontal cortex(IFC) and insula, even when the analysis was limited to previously medication-naïve patients. The implicated region of the brain is known to mediate cognitive control, time estimation, and attention.  Dr.Rubia also notes that other studies show that the IFC/Insula is needed for updating information and allocating attention to relevant stimuli.  

Another region implicate by the meta-analysis was the right putamen, a region that is rich in dopamine transporters. This finding is consistent with the fact that the dopamine transporter is the main target of stimulant medications.    

What is the potential clinical implication of these findings?  As Dr. Rubia and colleagues note, it is possible that the fMRI anomalies they identified could be used as a biomarker for ADHD or a biomarker to select patients who should respond optimally to stimulant medication. Although fMRI cannot be used as a clinical tool at this time, research of this sort is opening up new horizons for how we understand the etiology of ADHD and the mechanisms whereby medications exert their effects.

April 21, 2021

Meta-analysis Finds Association Between Maternal Polycystic Ovary Syndrome (PCOS) and ADHD in Offspring

The Background:

Women with polycystic ovary syndrome (PCOS) themselves show higher rates of ADHD. Because ADHD is partly heritable (meaning genes contribute to the condition), some of the increased ADHD seen in children of mothers with PCOS could come from shared genetic factors. In other words, a mother’s and her child’s increased risk might sometimes reflect common genes rather than an effect of the pregnancy itself. 

Beyond genetics, growing evidence points to maternal metabolic problems during pregnancy as another important risk factor for neurodevelopmental outcomes. PCOS is one of these conditions and is considered both potentially modifiable (treatable or manageable) and biologically plausible as a contributor to risk. PCOS affects an estimated 5–10% of women of reproductive age worldwide and is characterized by signs such as hyperandrogenism (higher-than-normal levels of “male” hormones), insulin resistance (poorer ability to use the hormone insulin, which can affect blood sugar and metabolism), and chronic low-grade inflammation. 

However, studies to date have not all reached the same conclusions. Some research suggests the association between maternal PCOS and offspring ADHD is stronger for girls, while other studies did not analyze results by child sex. Methodological differences make it harder to draw clear conclusions. 

The Study:

It’s important to note that the studies included in this meta-analysis were observational (cohort studies and case-control studies). Observational studies can identify associations (that two things occur together) but cannot prove that one causes the other. A cohort study follows people over time, and a case-control study compares people with a condition to similar people without it. 

The pooled results came from six studies that together included almost 1.4 million mother–child pairs and that adjusted for confounders (other factors that might influence the result, such as maternal age or socioeconomic status). After statistical adjustment, children of mothers with PCOS had about 40% greater odds of ADHD than children of mothers without PCOS. The analysis reported no evidence of publication bias (no clear sign that only positive studies were published) and zero heterogeneity (the results were consistent across the studies). 

There was no meaningful difference in results between cohort and case-control studies, and the meta-analysis did not find a significant difference in the association when comparing male and female offspring. 

The Take-Away:

The research team concluded that this large-scale synthesis found an association between maternal PCOS and higher odds of ADHD and other neuropsychiatric conditions in children. They suggested that children born to mothers with PCOS may benefit from developmental monitoring to identify and address problems early, while emphasizing that causal relationships have not been established. They called for further studies to confirm these findings and to investigate the biological and environmental mechanisms that might explain the association. Indeed, because women with PCOS show higher rates of ADHD than other women, we need genetically informed research designs to see if the reported association is confounded.

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October 1, 2026

Large Cohort Study Finds Dose-Response Association Between Food Insecurity and ADHD

The Background:

Food insecurity is a widespread public‑health problem. Food insecurity refers to limited or uncertain access to enough safe, nutritious food. This term is used to describe households that sometimes or often can’t afford enough food or can only buy cheaper, less‑healthy options. 

In the United States, almost eleven million children and teens (14%) lived in food‑insecure households in 2019. By 2023, the share of households with food‑insecure children and adolescents was estimated to have risen to about 18%. 

Food insecurity is linked to worse physical health in children, including conditions like anemia (low red‑blood‑cell count), asthma, and delays in physical or mental development. It is also associated with problems in thinking and conduct (for example, aggressive behavior, anxiety, depression, and trouble concentrating or sitting still). 

Those thinking and behavior problems can look a lot like ADHD (persistent patterns of inattention, hyperactivity, and impulsivity. This can make it hard for clinicians to tell whether symptoms come from ADHD itself, from the stress of poverty and food insecurity, or a mix of both. That overlap can complicate diagnosis and sometimes lead to misdiagnosis. 

Smaller recent studies have looked at mental‑health links and found higher odds of ADHD and other mental‑health conditions among food‑insecure children aged 5–11 years. In one set of findings, moderate food insecurity was associated with 50% greater odds of an ADHD diagnosis and severe food insecurity with about 67% greater odds relative to food‑secure children. 

The Study:

Because many past studies looked at single risk factors or only measured symptom severity, fewer investigations have focused specifically on household food insecurity as it relates to actual ADHD diagnoses and how that might matter for care. To address that gap, researchers used multiple years (2016–2022) of data from the U.S. National Survey of Children’s Health (NSCH). This survey is designed to be nationally representative and asks parents about their child’s health, including whether a doctor or other clinician has diagnosed ADHD. 

The study included 232,571 children and adolescents (ages 3–17) and used statistical methods to adjust for other factors that could affect ADHD risk. Those factors included the child’s sex and race/ethnicity; the mother’s age; family income expressed as a percentage of the federal poverty level (a government measure used to classify income groups); the highest level of parent education; adverse childhood experiences (such as exposure to abuse, household substance use, or parental separation); birthweight (for example, low birthweight); and not getting enough sleep. Adjusting for these variables helps isolate the association between food insecurity and ADHD, though it cannot prove cause and effect. 

The Results:

In this large, nationally representative sample, the researchers found a clear dose–response relationship: as the level of household food insecurity increased, so did the odds of a child having a clinician‑diagnosed ADHD (as reported by parents). In other words, greater food insecurity was linked to a higher likelihood of ADHD. 

Compared with children in households that “could always afford to eat good, nutritious meals” (the reference group), the study found the following increases in odds of ADHD: children in households that “could always afford enough to eat but not always the kinds of food we should eat” had about 30% greater odds; children in households that sometimes “could not afford enough to eat” had about 55% greater odds; and children in households that often “could not afford enough to eat” had about 80% greater odds. (Saying “30% greater odds,” etc., means the odds were 1.30, 1.55, and 1.80 times those of the reference group, respectively — this describes a relative increase, not the absolute percentage of children with ADHD.) 

The Take-Away:

The authors conclude that household food insecurity was associated with higher odds of parent‑reported clinician‑diagnosed ADHD in a dose‑response pattern. They suggest that reducing food insecurity (for example, ,by improving access to nutritious food and combining nutritional supports with mental‑health care) may help lower ADHD risk or reduce symptoms in some children. Reducing food insecurity should be a priority for society, but it is premature to conclude it will reduce the risk for ADHD. We know that parents with ADHD are more likely to lose their jobs and have lower incomes compared to parents with ADHD.  That might create food insecurity for their children who we know are at high risk for ADHD from genetic studies.  

 

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Meta-analysis Finds Long-term Exercise Associated with Moderate Improvements in Executive Functioning for Children and Adolescents with ADHD

The Background: 

Many studies have tried to determine whether exercise improves executive function in children and adolescents with ADHD, but their conclusions have not always agreed. To bring the evidence together more clearly, the research team re-analyzed the available randomized controlled trials using a statistical approach designed to handle the kinds of data common in this field. 

Executive functions are skills that help us control attention and behavior. The three core components are inhibitory control (the ability to stop or override impulses), working memory (holding and manipulating information in mind), and cognitive flexibility (switching between tasks or perspectives). Because a single study often reports multiple tests that tap these different skills, one study can contribute several related results (called effect sizes). Traditional meta-analysis typically treats each effect size as independent; when they are actually correlated, that can bias the combined estimate or force reviewers to discard useful data. 

To avoid those problems, the team used a three-level meta-analysis. In this model, variance in the data is separated into three sources: 

(1) sampling variance: the random error in each measured effect 

(2) within-study variance: differences between multiple effect sizes reported in the same study

(3) between-study variance: differences in effects from one study to another

Accounting for all three levels makes it possible to include every eligible effect size from each study, which preserves information and statistical power and reduces the risk that correlations among effect sizes will overstate results. 

The Study:

The review focused on long-term exercise interventions and also tested whether certain factors might change (or moderate) the effects. These potential moderators included participant age, which executive-function subcomponent was measured, the type of exercise, how long each session lasted, the total length of the intervention, and how often sessions occurred. 

To be included, studies had to be randomized controlled trials (RCTs) of children or adolescents aged 6–18 diagnosed with ADHD. RCTs randomly assign participants to an intervention or a comparison group and are considered a strong design for testing cause-and-effect. The exercise programs had to be structured and last at least six weeks. Comparison groups varied by study and could include usual care, medication, sedentary activities, health education, waiting lists, or everyday life without the specific exercise program. Fifteen studies including 658 participants met these criteria. 

The Results:

The three-level meta-analysis showed that long-term exercise interventions were associated with moderate-to-strong improvements in overall executive function. When statistical outliers were removed, the result remained positive: 13 RCTs with 598 participants showed moderate improvements. In plain terms, this suggests improvements that are noticeable and meaningful on average, not just tiny changes that are unlikely to matter in daily life. 

Those moderate gains appeared across all three executive-function domains  (inhibitory control, working memory, and cognitive flexibility, meaning the benefits were not limited to a single cognitive skill. The authors also examined exercise type: 

“Open-skill” activities, which require reacting to changing situations (for example, many team sports, martial arts sparring, or racket sports), produced moderate-to-large improvements. 

“Closed-skill” activities, which are more predictable and repetitive (for example, running or stationary cycling), showed only small, non-significant improvements in this analysis. 

The review also found dose-related patterns. Interventions lasting at least twelve weeks were about three times more effective than interventions of six to twelve weeks, and sessions longer than an hour were about twice as effective as shorter sessions. Benefits were largest among adolescents aged 13 and older. 

These patterns suggest that longer, more intensive programs, and those that involve open-skill activities, may produce larger gains. However, the authors caution that the overall certainty of the evidence was low. “Low certainty” means that limitations in the available studies (for example, small sample sizes, variability in methods, or possible bias) make it difficult to be confident that the observed effects will hold up exactly the same way in future research. Some subgroup findings (age, intervention duration, and others) were based on only a small number of effect sizes, so those moderator results should be treated as exploratory rather than definitive. 

The Take-Away:

In short, this three-level meta-analysis suggests that regular, structured exercise (particularly longer programs and open-skill activities) may help improve executive functions in children and adolescents with ADHD. The evidence is promising but not yet strong enough to be considered conclusive, and the authors recommend more, larger randomized trials to confirm specifically which types and doses of exercise are most effective.  Moreover, neither this meta-analysis or others show that exercise can replace standard treatments for reducing the core symptoms of ADHD (inattention, hyperactivity, impulsivity).

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September 11, 2026