Cookie Preferences
By clicking, you agree to store cookies on your device to enhance navigation, analyze usage, and support marketing. More Info
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
July 23, 2025
Methylphenidate (MPH) is one of the most widely-prescribed medications for children. Given that ADHD frequently persists over a large part of an individual’s lifespan, any side effects of medication initiated during childhood may well be compounded over time. With funding from the European Union, a recently released review of the evidence looked for possible adverse neurological and psychiatric outcomes.
From the outset, the international team recognized a challenge: “ADHD severity may be an important potential confounder, as it may be associated with both the need for long-term MPH therapy and high levels of underlying neuropsychiatric comorbidity.” Their searches found a highly heterogeneous evidence base, which made meta-analysis inadvisable. For example, only 25 of 39 group studies reported the presence or absence of comorbid psychiatric conditions; even among those, only one excluded participants with comorbidities. Moreover in only 24 of 67 studies was the type of MPH used (immediate or extended-release) specified. The team, therefore, focused on laying out an “evidence map” to help determine priorities for further research.
The team found the following breakdown for specific types of adverse events:
· Low mood/depression. All three non-comparative studies found MPH safe. Two large cohort studies, one with over 2,300 participants, and the other with 142,000, favored MPH over the non-stimulant atomoxetine. But many other studies, including a randomized controlled trial (RCT), had unclear results. Conclusion: “the evidence base regarding mood outcomes from long-term MPH treatment is relatively strong, includes two well-powered comparative studies, and tends to favor MPH.”
· Anxiety. Here again, all three non-comparative studies found MPH safe. But only two of seven comparative studies favored MPH, with the other five having unclear results. Conclusion: “while the evidence about anxiety as an outcome of long-term MPH treatment tends to favor MPH, the evidence base is relatively weak.”
· Irritability/emotional reactivity. A large cohort study with over 2,300 participants favored MPH over atomoxetine. Conclusion: “the evidence base is limited, although it includes one well-powered study that found in favor of MPH over atomoxetine.”
· Suicidal behavior/ideation. There were no non-comparative studies, but all five comparative studies favored MPH. That included three large cohort studies, with a combined total of over a hundred thousand participants, that favored MPH over atomoxetine. Conclusion: “the evidence base is relatively strong, and tends to favor MPH.”
· Bipolar disorder. A very large cohort study, with well over a quarter-million participants, favored MPH over atomoxetine. A much smaller cohort study comparing MPH with atomoxetine, with less than a tenth the number of participants, pointed toward caution. Conclusion: “the evidence base is limited and unclear, although it includes two well-powered studies.”
· Psychosis/psychotic-like symptoms. By far the largest study, with over 145,000 participants, compared MPH with no treatment and pointed toward caution. A cohort study with over 2,300 participants favored MPH over atomoxetine. Conclusion: “These findings indicate that more research is needed into the relationship between ADHD and psychosis, and into whether MPH moderates that risk, as well as research into individual risk factors for MPH-related psychosis in young people with ADHD.”
· Substance use disorders. A cohort study with over 20,000 participants favored MPH over anti-depressants, anti-psychotics, and no medication. Other studies looking at dosages and durations of treatment, age at treatment initiation, or comparing with no treatment or “alternative” treatment, all favored MPH except a single study with unclear results. Conclusion: “the evidence base … is relatively strong, includes one well-powered study that compared MPH with antipsychotic and antidepressant treatment, and tends to favor MPH.”
·Tics and other dyskinesias. Of four non-comparative studies, three favored MPH, the other, with the smallest sample size, urged caution. In studies comparing with dexamphetamine, pemoline, Adderall, or no active treatment, three had unclear results and two pointed towards caution. Conclusion: “more research is needed regarding the safety and management of long-term MPH in those with comorbidities or tic disorder.”
· Seizures or EEG abnormalities. With one exception, the studies had small sample sizes. The largest, with over 2,300 participants, compared MPH with atomoxetine, with inconclusive results. Two small studies found MPH safe, one had unclear results, and two others pointed towards caution. Conclusion: “While the evidence is limited and unclear, the studies do not indicate evidence for seizures as an AE of MPH treatment in children with no prior history more research is needed into the safety of long-term MPH in children and young people at risk of seizures.”
· Sleep Disorders. All three non-comparative studies found MPH safe, but the largest cohort study, with over 2,300 participants, clearly favored atomoxetine. Conclusion: “more research is needed into the relationship between ADHD, sleep, and long-term MPH treatment.”
· Other notable psychiatric outcomes. Two non-comparative studies, with 118 and 289 participants, found MPH safe. A cohort study with over 700 participants compared with atomoxetine, with inconclusive results. Conclusion: “there is limited evidence regarding long-term MPH treatment and other neuropsychiatric outcomes, and that further research may be needed into the relationship between long-term MPH treatment and aggression/hostility.”
Although this landmark review points to several gaps in the evidence base, it mainly supports prior conclusions of the US Food and Drug Administration) and other regulatory agencies (based on short-term randomized controlled trials) that MPH is safe for the treatment of ADHD in children and adults. Given that MPH has been used for ADHD for over fifty years and that the FDA monitors the emergence of rare adverse events, patients, parents, and prescribers can feel confident that the medication is safe when used as prescribed.
Helga Krinzinger, Charlotte L Hall, Madeleine J Groom,Mohammed T Ansari, Tobias Banaschewski, Jan K Buitelaar, Sara Carucci, DavidCoghill, Marina Danckaerts, Ralf W Dittmann, Bruno Falissard, Peter Garas,Sarah K Inglis, Hanna Kovshoff, Puja Kochhar, Suzanne McCarthy, Peter Nagy,Antje Neubert, Samantha Roberts, Kapil Sayal, Edmund Sonuga-Barke , Ian C KWong , Jun Xia, Alexander Zuddas, Chris Hollis, Kerstin Konrad, Elizabeth BLiddle and the ADDUCE Consortium, “Neurological and psychiatric adverse effectsof long-term methylphenidate treatment in ADHD: A map of the current evidence,”Neuroscience and Biobehavioral Reviews (2019) DOI: https://doi.org/10.1016/j.neubiorev.2019.09.023.
A new large-scale study has shed light on which treatments for attention-deficit/hyperactivity disorder (ADHD) in adults are most effective and best tolerated.
Researchers analyzed 113 randomized controlled trials involving nearly 15,000 adults diagnosed with ADHD. These studies included medications (like stimulants and atomoxetine), psychological therapies (such as cognitive behavioral therapy), and newer approaches like neurostimulation.
The Findings
Stimulant medications (lisdexamfetamine and methylphenidate) as well as selective norepinephrine reuptake inhibitors (SNRI) (atomoxetine) were the only treatments that consistently reduced core ADHD symptoms—both from the perspective of patients and clinicians. It may be worth noting that atomoxetine, while effective, was less well tolerated, with more people dropping out due to side effects.
Psychological therapies such as CBT, mindfulness, and psychoeducation showed some benefits, but mainly according to clinician ratings—not necessarily from the patients themselves. Neurostimulation techniques like transcranial direct current stimulation also showed some improvements, but only in limited contexts and with small sample sizes.
Conclusion
So, what does this mean for people navigating ADHD in adulthood? Stimulant medications remain the most effective treatment for managing ADHD symptoms day-to-day but nonstimulant medication are not far behind, which is good given the problems we’ve had with stimulant shortages. This study also supports structured psychotherapy as a viable treatment option, especially when used in conjunction with medication.
The study emphasizes the importance of ongoing, long-term research and the need for treatment plans that are tailored to the individual ADHD patient– Managing adult ADHD effectively calls for flexible, patient-centered care.
-----
Struggling with side effects or not seeing improvement in your day-to-day life? Dive into a step-by-step journey that starts with the basics of screening and diagnosis, detailing the clinical criteria healthcare professionals use so you can be certain you receive an accurate evaluation. This isn’t just another ADHD guide—it’s your toolkit for getting the care you deserve. This is the kind of care that doesn’t just patch up symptoms but helps you unlock your potential and build the life you want. Whether you’ve just been diagnosed or you’ve been living with ADHD for years, this booklet is here to empower you to take control of your healthcare journey.
Proceeds from the sale of this book are used to support www.ADHDevidence.org.
With the growth of the Internet, we are flooded with information about attention deficit hyperactivity disorder from many sources, most of which aim to provide useful and compelling "facts" about the disorder. But, for the cautious reader, separating fact from opinion can be difficult when writers have not spelled out how they have come to decide that the information they present is factual.
My blog has several guidelines to reassure readers that the information they read about ADHD is up-to-date and dependable. They are as follows:
Nearly all the information presented is based on peer-reviewed publications in the scientific literature about ADHD. "Peer-reviewed" means that other scientists read the article and made suggestions for changes and approved that it was of sufficient quality for publication. I say "nearly all" because in some cases I've used books or other information published by colleagues who have a reputation for high-quality science.
When expressing certainty about putative facts, I am guided by the principles of evidence-based medicine, which recognizes that the degree to which we can be certain about the truth of scientific statements depends on several features of the scientific papers used to justify the statements, such as the number of studies available and the quality of the individual studies. For example, compare these two types of studies. One study gives drug X to 10 ADHD patients and reported that 7 improved. Another gave drug Y to 100 patients and a placebo to 100 other patients and used statistics to show that the rate of improvement was significantly greater in the drug-treated group. The second study is much better and much larger, so we should be more confident in its conclusions. The rules of evidence are fairly complex and can be viewed at the Oxford Center for Evidenced Based Medicine (OCEBM;http://www.cebm.net/).
The evidenced-based approach incorporates two types of information: a) the quality of the evidence and b) the magnitude of the treatment effect. The OCEBM levels of evidence quality are defined as follows (higher numbers are better:
Non-randomized, controlled studies. In these studies, the treatment group is compared to a group that receives a placebo treatment, which is a fake treatment not expected to work.
It is possible to have high-quality evidence proving that a treatment works but the treatment might not work very well. So it is important to consider the magnitude of the treatment effect, also called the "effect size" by statisticians. For ADHD, it is easiest to think about ranking treatments on a ten-point scale. The stimulant medications have a quality rating of 5 and also have the strongest magnitude of effect, about 9 or 10.Omega-3 fatty acid supplementation 'works' with a quality rating of 5, but the score for the magnitude of the effect is only 2, so it doesn't work very well. We have to take into account patient or parent preferences, comorbid conditions, prior response to treatment, and other issues when choosing a treatment for a specific patient, but we can only use an evidence-based approach when deciding which treatments are well-supported as helpful for a disorder.
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%).
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.
...
Struggling to get the care you need to manage your ADHD? Support The ADHD Evidence Project and get this step-by-step guide to getting the treatment you deserve: https://bit.ly/41gIQE9
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.
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.
Methylphenidate is an effective treatment for ADHD in adults who also have bipolar disorder (BD), but it carries a potential risk of triggering manic episodes. Current guidelines therefore recommend using it only alongside mood-stabilizing medication. A new study using French nationwide claims data sought to test and extend those recommendations with greater statistical power than previous research.
The study built on findings by Viktorin et al. (2017), who observed that adults with BD not taking mood stabilizers had more than a sixfold higher risk of manic events (defined as hospitalization for mania or a new antimanic prescription) within six months of starting methylphenidate. Patients on mood-stabilizing treatment, by contrast, showed nearly half the baseline risk in the first three months. Those findings were limited, however, by small event counts (fewer than 61 manic episodes) and an effect that did not persist beyond the initial three-month window.
To build on this, researchers drew on the French National Health Data System (which is a claims database covering more than 60 million people) spanning 2008 to 2024. The final sample included 6,022 adults with BD (56% women) who had started methylphenidate. Using a self-controlled design, the study compared each patient's rate of manic events in the six months before their first methylphenidate prescription with the rate in the six months after, effectively eliminating stable individual differences as a confound.
Patients were classified as receiving continuous mood-stabilizing treatment if they had been dispensed at least two courses of specific antipsychotics (aripiprazole, olanzapine, or quetiapine) or mood stabilizers (lithium or valproate) in the nine months before starting methylphenidate, including at least one dispensation in the final six months of that window.
The results largely confirmed the earlier findings. Among the 2,745 patients not on mood stabilizers, the rate of inpatient mania diagnosis was 5.1 times higher in the first three months after starting methylphenidate, though this elevation fell to a non-significant level over the subsequent three months. Patients receiving continuous mood-stabilizing treatment showed no statistically significant change in mania risk across the full six-month post-initiation period. A formulation-specific pattern also emerged: patients without mood-stabilizing treatment had a 2.5-fold higher risk associated with extended-release methylphenidate, while no significant risk increase was seen with the immediate-release formulation or in treated patients regardless of formulation.
The authors conclude that methylphenidate at doses below 30 mg does not appear to elevate manic relapse risk when prescribed alongside mood stabilizers. The elevated risk seen in untreated patients, particularly with extended-release formulations, must be interpreted cautiously, given limited statistical power and the likelihood that it partly reflects the natural fluctuation of manic relapse over time. The authors flag this as an inherent limitation of self-controlled survival analyses when studying drug-induced mania, where temporal trends in the underlying condition can be difficult to disentangle from treatment effects.
_logo%201.svg)
