October 24, 2025

Meta-analysis of Transcranial Direct Current Stimulation Still Yields Little Sign of Efficacy

Background:

Despite recommendations for combined pharmacological and behavioral treatment in childhood ADHD, caregivers may avoid these options due to concerns about side effects or the stigma that still surrounds stimulant medications. Alternatives like psychosocial interventions and environmental changes are limited by questionable effectiveness for many patients. Increasingly, patients and caregivers are seeking other therapies, such as neuromodulation – particularly transcranial direct current stimulation (tDCS). 

tDCS seeks to enhance neurocognitive function by modulating cognitive control circuits with low-intensity scalp currents. There is also evidence that tDCS can induce neuroplasticity. However, results for ADHD symptom improvement in children and adolescents are inconsistent. 

The Method:

To examine the evidence more rigorously, a Taiwanese research team conducted a systematic search focusing exclusively on randomized controlled trials (RCTs) that tested tDCS in children and adolescents diagnosed with ADHD. They included only studies that used sham-tDCS as a control condition – an essential design feature that prevents participants from knowing whether they received the active treatment, thereby controlling for placebo effects. 

The Results:

Meta-analysis of five studies combining 141 participants found no improvement in ADHD symptoms for tDCS over sham-TDCS. That held true for both the right and left prefrontal cortex. There was no sign of publication bias, nor of variation (heterogeneity) in outcomes among the RCTs.  

Meta-analysis of six studies totaling 171 participants likewise found no improvement in inattention symptoms, hyperactivity symptoms, or impulsivity symptoms for tDCS over sham-TDCS. Again, this held true for both the right and left prefrontal cortex, and there was no sign of either publication bias or heterogeneity. 

Most of the RCTs also performed follow-ups roughly a month after treatment, on the theory that induced neuroplasticity could lead to later improvements. 

Meta-analysis of four RCTs combining 118 participants found no significant improvement in ADHD symptoms for tDCS over sham-TDCS at follow-up. This held true for both the right and left prefrontal cortex, with no sign of either publication bias or heterogeneity. 

Meta-analysis of five studies totaling 148 participants likewise found no improvement in inattention symptoms or hyperactivity symptoms for tDCS over sham-TDCS at follow-up. AS before, this was true for both the right and left prefrontal cortex, with no sign of either publication bias or heterogeneity. 

The only positive results came from meta-analysis of the same five studies, which reported a medium effect size improvement in impulsivity symptoms at follow-up. Closer examination showed no improvement from stimulation of the right prefrontal cortex, but a large effect size improvement from stimulation of the left prefrontal cortex

Interpretation: 

It is important to note that the one positive result was from three RCTs combining only 90 children and adolescents, a small sample size. Moreover, when only one of sixteen combinations yields a positive outcome, that begins to look like p-hacking for a positive result. 

In research, scientists use something called a “p-value” to determine if their findings are real or just due to chance. A p-value below 0.05 (or 5%) is considered “statistically significant,” meaning there's less than a 5% chance the result happened by pure luck. 

When testing twenty outcomes by this standard, one would expect one to test positive by chance even if there is no underlying association. In this case, one in 16 comes awfully close to that. 

To be sure, the research team straightforwardly reported all sixteen outcomes, but offered an arguably over-positive spin in their conclusion: “Our study only showed tDCS-associated impulsivity improvement in children/adolescents with ADHD during follow-ups and anode placement on the left PFC. ... our findings based on a limited number of available trials warrant further verification from large-scale clinical investigations.” 

Chun-Bin Tunga, Shun-Chin Liang, Cheuk-Kwan Sun, Yu-Shian Cheng, and Kuo-Chuan Hung, “Behavioral outcomes after tDCS treatment during immediate post-intervention and follow-up periods in children and adolescents diagnosed with attention-deficit/hyperactivity disorder: a systematic review and meta-analysis on randomized sham-controlled trials,” Journal of Psychiatric Research 191 (2025) 8-14, https://doi.org/10.1016/j.jpsychires.2025.09.008

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New Non-Stimulant ADHD Drug: Clinical Trial Results

The Newest Non-stimulant Medication for ADHD

Centanafadine, which is currently under investigation as a treatment for ADHD, will be the first triple reuptake inhibitor for the disorder if it is approved by the FDA. It improves norepinephrine, dopamine and serotonin levels. This new medication is not a stimulant, but due to the dopamine component, it has a stimulant-like effect in patients. In adults, two phase 3 trials and a year-long extension have shown sustained benefits and a tolerable safety profile, laying the groundwork for pediatric research.

Based on this study, improvement was already noticeable after the first week and held steady through week 6. The lower dose (164.4 mg) didn’t separate from placebo, reminding us that getting the dose right will be critical. The effect size was smaller than what is seen for stimulants but 50% of patients had excellent outcomes as indicated by reductions in the ADHD-RS of 50% or more.

Side effect patterns look familiar to anyone who prescribes ADHD medications; loss of appetite, nausea and headaches topped the list. About half of teens on the higher dose reported at least one treatment-emergent adverse event, compared with a quarter of those on placebo. Severe reactions were rare but did include isolated liver enzyme spikes, rash, and a few reports of aggression or somnolence. For everyday practice, that translates to routine growth checks, a look at baseline liver function, and clear guidance to families about reporting rashes or mood changes promptly.

The researchers noted that the study had certain limitations, including limited generalizability to adolescents beyond North America, the exclusion of teacher ratings on the ADHD-RS-5 scale and the study’s short duration. They added that future studies should explore long-term treatment outcomes and efficacy compared with other ADHD treatments, as well as its effect on treating ADHD with comorbid conditions.

Why should this matter to clinicians already juggling multiple non-stimulant options for ADHD?

First, speed. Centanafadine separated from placebo within a week. In this regard, it might be closer to stimulants than to the multi-week ramp-up we expect from current non-stimulants. Second, it offers another option when stimulants are contraindicated or poorly tolerated, or when they raise diversion concerns. Its mechanism also makes it intriguing for patients who need both norepinephrine and dopamine coverage but prefer to avoid schedule II drugs. Because it also improves serotonergic transmission, it may be useful for some of ADHD’s comorbidities (see our new article for evidence about serotonin’s role in these disorders).

Keep in mind that centanafadine for ADHD is still investigational, so participation in clinical trials remains the only access route.

August 5, 2025

Transcranial Direct Current Stimulation: Can It Treat ADHD?

How effective and safe is transcranial direct current stimulation for treating ADHD?

ADHD is hypothesized to arise from 1) poor inhibitory control resulting from impaired executive functions which are associated with reduced activation in the dorsolateral prefrontal cortex and increased activation of some subcortical regions; and 2)hyperarousal to environmental stimuli, hampering the ability of the executive functioning system, particularly the medial frontal cortex, orbital and ventromedial prefrontal areas, and subcortical regions such as the caudate nucleus, amygdala, nucleus accumbens, and thalamus, to control the respective stimuli.

These brain anomalies, rendered visible through magnetic resonance imaging, have led researchers to try new means of treatment to directly address the deficits. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that uses a weak electrical current to stimulate specific regions of the brain.

Efficacy:

A team of researchers from Europe and ran performed a systematic search of the literature and identified fourteen studies exploring the safety and efficacy of tDCS. Three of these studies examined the effects on ADHD symptoms. They found a large effect size for the inattention subscale and a medium effect size for the hyperactivity/impulsivity. Yet, as the authors cautioned, "a definite conclusion concerning the clinical efficacy of tDCS based on the results of these three studies is not possible."

The remaining studies investigated the effects on specific neuropsychological and cognitive deficits in ADHD:

  •  Working memory was improved by anodal stimulation - but not cathodal stimulation - of the left dorsolateral prefrontal cortex. Anodal stimulation of the right inferior frontal gyrus had no effect.
  •  Response inhibition: Anodal stimulation of the left or right dorsolateral prefrontal cortex was more effective than anodal stimulation of the bilateral prefrontal cortex.
  • Motivational and emotional processing was improved only with stimulation of both the dorsolateral prefrontal cortex and orbitofrontal cortex.

The fact that heterogeneity in the methodology of these studies made meta-analysis impossible means these results, while promising, cannot be seen as in any way definitive.

Safety:

Ten studies examined childhood ADHD. Three found no adverse effects either during or after tDCS. One study reported a feeling of "shock" in a few patients during tDCS. Several more reported skin tingling and itching during tDCS. Several also reported mild headaches.

The four studies of adults with ADHD reported no major adverse events. One study reported a single incident of acute mood change, sadness, diminished motivation, and tension five hours after stimulation. Another reported mild instances of skin tingling and burning sensations.

To address side effects such as tingling and itching, the authors suggested reducing the intensity of the electrical current and increasing the duration. They also suggested placing electrodes at least 6 cm apart to reduce current shunting through the ski. For children, they recommended the use of smaller electrodes for better focus in smaller brains.

The authors concluded, "The findings of this systematic review suggest at least a partial improvement of symptoms and cognitive deficits in ADHD by tDCS. They further suggest that stimulation parameters such as polarity and site are relevant to the efficacy of tDCS in ADHD. Compared to cathodal stimulation, Anodal tDCS seems to have a superior effect on both the clinical symptoms and cognitive deficits. However, the routine clinical application of this method as an efficient therapeutic intervention cannot yet be recommended based on these studies ..."

January 10, 2022

Meta-Analysis Finds No Significant Benefit For ADHD Patients in tCDS

New Meta-analysis Finds No Significant Gains from Transcranial Direct Stimulation (tCDS)

Noting that "despite a lack of solid evidence for their use, rTMS [repetitive transcranial magnetic stimulation]and tDCS [transcranial direct current stimulation] are already offered clinically and commercially in ADHD," and that a recent meta-analysis of ten tDCS studies found small but significant improvements in outcomes, but had several methodological shortcomings and did not include two studies reporting mostly null effects, a team of British neurologists performed a meta-analysis of all twelve sham-controlled, non-open-label, studies found in a comprehensive search of the peer-reviewed literature.

Ten of the twelve randomized-controlled trials used anodal stimulation of the dorsolateral prefrontal cortex, while the other two used anodal stimulation of the right inferior frontal cortex.

The trials explored several measures of cognition. The research team carried out a meta-analysis of all twelve trials, with a total of 232 participants, and found no significant improvement in attention scores from CDC, relative to sham stimulation. A second meta-analysis, of eleven trials with a total of 220 participants, assessed the efficacy of tDCS on improving inhibition scores, and again found no significant effect. A third meta-analysis, encompassing eight trials with a total of 124 participants, evaluated the efficacy of tDCS on improving processing speed scores, once again finding no significant effect.

The latter two meta-analyses approached the border of significance, prompting the authors to speculate that larger sample sizes could bring the results just over the threshold of significance. Even so, effect sizes would be small.

It is also possible that the trials focused on regions of the brain suboptimal for this objective, and thus the authors "cannot rule out the possibility that stimulation of other prefrontal regions (such as the right hemispheric inferior frontal cortex or dorsolateral prefrontal cortex or parietal regions), multiple session tDCS or tDCS in combination with cognitive training could improve clinically or cognitive functions in ADHD."

As to concerns about safety, on the other hand, "stimulation was well-tolerated overall."

The authors concluded that based on current evidence, tDCS of the dorsolateral prefrontal cortex cannot yet be recommended as an alternative Neurotherapy for ADHD.

February 15, 2022

Fractured Trust, Delayed Care: What Rising Health Misinformation Means for ADHD

When a patient sits down in an examination room today, their physician is rarely the first voice they have heard regarding their symptoms. More often, an algorithm got there first.

According to a nationwide survey by The Physicians Foundation conducted with Medscape, medical misinformation is no longer a peripheral nuisance;  it is a daily clinical crisis. Nearly all surveyed physicians (99.9%) reported that their patients  had been influenced by medical misinformation over the past year.  

While misinformation affects every discipline from oncology to cardiology, few conditions sit as squarely in the algorithmic crosshairs as ADHD. From viral 30-second video clips trivializing complex executive dysfunction to predatory wellness campaigns attacking evidence-based medications, the attack on evidence directly threatens the well-being of children and adults living with ADHD.

Key Findings from The Physicians Foundation

The survey, which captured perspectives from over 1,000 practicing physicians, paints a sobering picture of how unverified information disrupts modern medicine:

  • Erosion of the Patient-Doctor Alliance: One in three physicians (34%) report frequent breakdowns of trust caused by patient misinformation, while 31% report regular conflict during clinical visits.
  • The Social Media Machine: 85% of physicians identify social media as a primary driver of misinformation, and 48% name it as the single most damaging source. Compounding the issue, 43% of physicians have no confidence that their patients know how to locate reliable, peer-reviewed medical guidance online.
  • Direct Harm to Clinical Outcomes: Misinformation does not only alter beliefs; it changes behavior. Physicians reported widespread treatment nonadherence (49%), heightened patient anxiety (66%), and outright refusal of recommended evidence-based care (45%).
  • Primary Care on the Front Lines: 70% of primary care clinicians say that misinformation actively impairs their ability to provide quality care. Yet, 34% feel they lack the visit time to properly deconstruct false claims, and 74% lack the institutional tools and support to bridge the divide.

The challenge is especially acute in communities already facing systemic healthcare hurdles:

As the survey illustrates, 38% of rural physicians encounter "a great deal" of health misinformation, far exceeding their suburban (21%) and urban (25%) peers. In rural and underserved regions, where access to developmental pediatricians and psychiatrists is already scarce, online narratives frequently fill the void left by provider shortages.


Why ADHD Is Ground Zero for Health Misinformation

Despite decades of neurobiological research confirming its validity, ADHD remains uniquely vulnerable to digital distortions in three distinct ways:

1. The Dueling Traps: "Life Hack" Trivialization vs. Denialism

Social media platforms host billions of views under ADHD-related tags. While digital awareness has helped destigmatize mental health, it frequently collapses nuanced clinical criteria into broad, relatable personality traits such as zoning out during a boring meeting, misplacing keys, or feeling restless.

This creates two opposing misinformation hazards:

  • Diagnostic Confusion and Friction: When individuals arrive seeking validation for self-diagnoses based on viral video check-lists, clinicians must conduct careful differential diagnoses to rule out trauma, generalized anxiety, sleep apnea, or mood disorders. When a physician explains that everyday distraction does not automatically equal ADHD, the encounter can quickly slide into the 31% of visits marred by conflict.
  • Legitimacy Denial: At the opposite extreme, pervasive internet subcultures claim ADHD is a "fictional construct" invented by pharmaceutical companies or the consequence of modern screen use and food additives. This narrative confuses parents and patients and leads them away from medical care when they decide that ADHD is not a disorder needing treatment.

2. Medication Stigma and Treatment Nonadherence

The survey found that 49% of doctors frequently encounter medication nonadherence and 45% face treatment refusal due to misinformation.

In ADHD care, this finding is acutely visible around stimulant pharmacotherapy. First-line stimulant medications have high response rates and extensive safety profiles spanning decades. Yet online narratives persistently frame them as dangerous narcotics, accusing parents of "drugging their children" or claiming medications permanently alter a child's brain.

Terrified parents frequently delay initiating care or discontinue effective regimens without clinical oversight, turning instead to unproven, expensive alternative supplements, unverified nootropics, or restrictive elimination diets.

3. Escalating Anxiety and Parental Guilt

With 66% of physicians observing increased patient anxiety driven by online health claims, the emotional toll on families cannot be overstated. Parents of newly diagnosed children are inundated with contradictory advice: one post warns that failing to medicate guarantees academic failure, while another claims that medicating guarantees addiction.

Adults navigating a new diagnosis experience similar distress, second-guessing their lived experiences and feeling deep shame over their executive dysfunction.

4. The 15-Minute Primary Care Bottleneck

Because pediatricians and family physicians handle most ADHD diagnoses and management, the survey’s warning that 70% of primary care providers feel hamstrung by misinformation hits ADHD patients first.

Deconstructing a viral video, explaining the difference between therapeutic stimulant dosing and substance misuse, and addressing years of internalized stigma takes time. In a standard 15-to-20-minute primary care visit, providers are forced to choose between rushing through diagnostic assessments or leaving patients' misinformed fears unaddressed.

Rebuilding the Partnership: Steps for Patients, Families, and Providers

Addressing the erosion of trust requires practical, collaborative shifts from both sides of the examination table:

For Patients and Caregivers

  • Bring Your Social Feeds to Your Doctor: If you find an ADHD video, article, or forum post that resonates with you or frightens you, share it directly with your provider. Frame it as an open question: "I saw this claim about stimulant tolerance online.  Can you walk me through what the medical evidence actually shows?"
  • Rely on Vetted Advocacy Organizations: Replace algorithmic feeds with non-commercial, evidence-based resources such as CHADD (Children and Adults with Attention-Deficit/Hyperactivity Disorder), the American Academy of Pediatrics (AAP), and the American Academy of Child and Adolescent Psychiatry (AACAP) and www.ADHDevidence.org.
  • Treat Diagnosis as an Investigation, Not a Quick Label: Understand that a thorough diagnostic evaluation involves standardized rating scales across multiple environments (home, school, work) and history taking. Thoroughness protects you from misdiagnosis.

For Healthcare Providers and Systems

  • Acknowledge Online Spaces Without Dismissal: Rather than responding to social media mentions with frustration, validate the patient’s search for understanding: "I'm glad you're looking into ways to manage your executive functioning. Let's look at what is clinically proven to help."
  • Provide "Information Prescriptions": Anticipate common fears by proactively handing parents and adult patients trusted, digestible fact sheets on ADHD medication safety and behavioral accommodations before they turn to search engines.
  • Advocate for Structural Reform: As The Physicians Foundation emphasizes, health systems must allocate longer appointment windows and behavioral health navigation resources for neurodevelopmental evaluations so clinicians have the time required to build lasting trust.

Medical misinformation thrives in the gap between a patient's vulnerability and the clinical system's time constraints. By recognizing how digital noise distorts ADHD, patients and clinicians can work together to replace viral anxiety with evidence-based care.

Japan’s Annual Socioeconomic Burden from ADHD Estimated at $11 billion

The Background:

Adults with ADHD often struggle more at work than their peers without ADHD. They tend to underperform on job tasks, advance less in their careers, miss more workdays, and face higher rates of unemployment. Research from several countries, including Japan, points to two main channels through which ADHD erodes workplace productivity: absenteeism, or missing work entirely, and presenteeism, showing up but performing below one’s usual capacity. Both problems typically trace back to ADHD’s core symptoms: difficulty sustaining attention, managing time, staying organized, and navigating relationships with coworkers and supervisors. 

Stigma compounds these challenges. Employers and the public often have limited understanding of how ADHD manifests in adults, which can translate into unfair treatment or diminished job opportunities. That fear of judgment, in turn, discourages some people from seeking a psychiatric evaluation in the first place, delaying diagnosis and treatment, and with it, delaying access to support that could improve both their work performance and daily functioning. 

Japan does offer medical care and workplace support for adults with ADHD. Options include social skills training, which teaches practical strategies for communication and collaboration; self-reliance support programs that help with daily living and job management; and, in more severe cases, a disability pension for those unable to work. Still, it remains unclear whether these employment-support services are robust enough to help people who want to work actually secure and hold onto steady jobs. 

The impact of ADHD extends beyond the individual diagnosed. Supporting a family member with ADHD can be emotionally and logistically demanding, often cutting into a caregiver’s own capacity to work and earn, meaning that the economic toll of ADHD ripples outward.

The Research: 

Most prior research on the economic costs of ADHD, in both children and adults, has come from the United States and Europe, focusing on medical expenses, lost productivity, and social support spending. Until recently, no one had attempted a comparable estimate for adult ADHD in Japan or elsewhere in Asia. 

To address that gap, a Japanese research team conducted a cross-sectional observational study (meaning they gathered data at a single point in time and examined existing patterns rather than testing an intervention). They drew on three sources: a retrospective review of medical insurance claims, a web-based survey of affected individuals, and official government statistics. Combining these, they estimated annual costs from a societal perspective, accounting for medical expenses, lost work productivity, and government welfare spending, as well as productivity losses among family caregivers. 

The claims analysis relied on JMDC, a nationwide database of insurance receipts and medical examination records spanning multiple health insurers and covering 14 million residents. Within it, the researchers identified 30,730 adult outpatients diagnosed with ADHD. 

The Results:

Annual medical costs per adult with ADHD  (combining outpatient visits and medication) averaged 284,000 yen (about $1,750). Scaling this figure to match the age and sex distribution of Japan’s adult population produced a nationwide estimate of 74 billion yen (about $455 million). 

A separate web-based survey found that, after statistical matching, nearly half of adults with ADHD received a disability pension, yielding a nationwide estimate of 95 billion yen (about $585 million) in ADHD-related pension payments. Including public employment support services, total social welfare spending reached 390 billion yen (about $2.4 billion). 

Workplace productivity losses were substantial as well. With an unemployment rate more than four percentage points higher than the general population, unemployment-related losses among adults with ADHD totaled an estimated 50 billion yen. Lower average incomes among those employed accounted for a further 315 billion yen. Once absenteeism and presenteeism were factored in, total productivity losses reached 570 billion yen (about $3.5 billion). 

Family members bore a comparable burden: productivity losses among adult relatives of people with ADHD were estimated at 540 billion yen (about $3.3 billion). 

Taken together, these figures point to a nationwide socioeconomic burden of 1.6 trillion yen (roughly $11 billion), equivalent to nearly $30,000 per adult with ADHD. 

The Take-Away:

“This study, the first estimate of the annual socioeconomic burden of adult ADHD in Japan, underscores the necessity of providing appropriate support to adult patients with ADHD and their families and the prevention of comorbidities,” the research team concluded. “In particular, measures to support participation in the workplace to improve patients’ quality of life and reduce the social and economic burden should be explored. Furthermore, it is hoped that estimating the annual socioeconomic burden of adult ADHD will help clarify policy priorities in Japan.” 

Untreated ADHD Nearly Doubles Risk of Motor Vehicle Crashes

Untreated ADHD nearly doubles risk of motor vehicle crashes, new meta-analysis finds

The Background:

Motor vehicle crashes remain one of the most significant public health challenges in the United States. In 2022 alone, nearly 44,000 people died on American roads, and more than 2.6 million crash-related injuries required emergency care. Most people are familiar with the usual suspects: drunk driving, speeding, and distracted driving from phones. These risks are well-documented and the focus of ongoing public safety campaigns. 

But a serious risk factor has been flying under the radar: untreated ADHD. Despite receiving little attention from the public, policymakers, or transportation safety agencies, it may belong in the same conversation as these better-known dangers. 

ADHD is not currently recognized by the National Highway Traffic Safety Administration as a driving risk factor; yet inattention and impulsivity, two of its defining features, are consistently cited as common contributors to crashes. Beyond these core symptoms, adults with ADHD may also experience emotional dysregulation, which can further impair driving behavior. 

The Research:

Prior studies on ADHD and crash risk have produced estimates ranging from a 5% to a 70% increase. This massive heterogeneity has made it difficult to draw firm conclusions. This new meta-analysis set out to offer some clarity on these numbers. 

Researchers focused specifically on adults aged 18 to 65 with a formal ADHD diagnosis who were not receiving treatment, comparing them to controls without ADHD. Four studies met these criteria, collectively covering more than 2.75 million people. 

The Results:

The findings were striking: untreated ADHD was associated with a 93% increase in crash risk (95% confidence interval: 88%–99%). There was no evidence of publication bias. Although there was meaningful variation across studies, most of it stemmed from the smallest study  (just 36 participants)  which reported an outlier estimate of a 16-fold increase. 

To put the 93% figure in context: a separate meta-analysis found that alcohol use is associated with a 150% increase in crash risk. Another way to understand just how significant this risk really is, untreated ADHD raises crash risk by more than half as much as alcohol does.

The analysis also found a dose-response relationship between ADHD symptom severity and crash risk: each incremental increase in symptom severity corresponded to a 5–6% higher crash risk. At the highest severity levels, crash risk approached that associated with alcohol use. This gradient reinforces that we're not looking at a binary distinction between “has ADHD” and “doesn’t” — the worse the symptoms, the greater the danger on the road. 

The Takeaway:

These findings have practical implications for patients, families, clinicians, and policymakers alike. Untreated ADHD is not a minor footnote in the driving safety literature; rather, it is a substantial, measurable, and potentially modifiable risk factor. The question of whether and how it should be factored into licensing policy, clinical practice, and public health messaging deserves serious attention. 

August 28, 2026