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May 23, 2025
The United Kingdom has a National Health Service (NHS) that encompasses virtually its entire population, with free access. The NHS records facilitate conducting nationwide studies.
The Study
Using electronic health records from 794 primary care practices (roughly one in ten UK practices), largely representative of the UK population, a research team used mortality data to explore the life expectancy of adults diagnosed with ADHD compared with adults not diagnosed with ADHD.
For each adult diagnosed with ADHD, the team sampled ten controls matched by age, sex, and primary care practice. They identified 30,039 individuals with an ADHD diagnosis in their electronic health records and matched them with 300,390 without an ADHD diagnosis.
The team also gathered data on socioeconomic deprivation, diabetes, elevated cholesterol, hardening of the coronary arteries, high blood pressure, chronic respiratory disease, epilepsy, anxiety, depression, severe mental illness, self-harm/suicide, autism, intellectual disability, personality disorder, current smoking, and potentially harmful alcohol use. All these conditions examined at baseline were more common among participants with ADHD than comparison participants.
Both men and women with ADHD were about twice as likely to die during follow-up as Those without ADHD. A diagnosis of ADHD was associated with a 6.8-year reduction of life expectancy in males and an 8.6-year reduction of life expectancy in females.
Conclusion
The authors wrote, “We believe that this is unlikely to be because of ADHD itself and likely caused by modifiable factors such as smoking, unmet mental and physical health support, and unmet treatment needs. The findings illustrate an important inequity that demands urgent attention.”
They also noted, “…we did not adjust for socioeconomic status (SES), as we believe that SES is best understood as part of the causal pathway between ADHD and premature mortality (i.e. SES is a mediator).” These results confirm other studies which also document that those with ADHD have a decreased life expectancy, primarily due to accidents and suicide.
Elizabeth O’Nions, Céline El Baou, Amber John, Dan Lewer, Will Mandy, Douglas G.J. McKechnie, Irene Petersen, and Josh Stott, “Life expectancy and years of life lost for adults with diagnosed ADHD in the UK: matched cohort study,” The British Journal of Psychiatry (2025), https://doi.org/10.1192/bjp.2024.199.
Researchers from the Swedish Department of Global Public Health, the Swedish Transport Agency, and the Swedish National Road and Transport Research Institute collaborated in a nationwide population study of motor vehicle crashes among the elderly, defined as 65 and older.
They availed themselves of the country's all-encompassing national registers to identify the anonymized records of all such drivers from 2011 through 2016. That enabled them to compare crash records of those with known driving-impairing conditions with matched drivers who had no record of such conditions.
They looked only at road traffic crashes that resulted in injury to the driver or a passenger. For anyone with multiple crash records, they only looked at the first.
This was a case-control study, with two controls matched to each case wherever possible. For every case of a 65 or older driver involved in an injurious crash, the team randomly matched two individual controls by sex, birth year, municipality of residence, and other medical conditions. Place of residence was used to distinguish residents of large cities, who would tend to drive less frequently and in denser traffic, from those in small towns and rural areas. To minimize controls that never drive, only those with a driver's license and car were considered.
Of the thirteen medical conditions examined, elderly drivers with "ADHD, autism spectrum disorder, and similar conditions" had by far the highest odds of being in crashes that resulted in injury "at almost three times the rate of those without those conditions."
But note carefully the serious limitations in the data:
Taiwan has a single-payer healthcare system that covers virtually every inhabitant (99.5%). That makes it relatively easy to track healthcare issues using its comprehensive National Health Insurance Research Database.
This database maintains a subset, the Longitudinal Health Insurance Database (LHID), consisting of a million persons, with no significant differences in sex, age, or healthcare use from the parent database.
A Taiwanese research team used the LHID to identify 114,486 individuals diagnosed with ADHD from 1997 to 2013. It then compared their motor vehicle (including motorcycles, which are extremely common in Taiwan) crash patterns with 338,261 normally developing controls from the same database.
Adjusting for sex, age, and psychiatric comorbidities, persons with ADHD were about a fifth (19%)more likely to be in traffic crashes. Breaking it down further by sex, women with ADHD were no more likely to be in crashes, but men with ADHD were about a quarter (24%) more likely than their healthy counterparts.
Since the database also tracks pharmaceutical prescriptions, the team also looked into the effect of methylphenidate (MPH), the medication that is the first-line treatment for ADHD under Taiwanese guidelines, and the only approved stimulant. Atomoxetine, a non-stimulant, is used where MPH is either ineffective or not indicated for any other reason and is only used in 4% of all cases.
Of the 114,486 persons diagnosed with ADHD, 89,826 used MPH, and 24,660 did not.
Compared with persons with ADHD who were not on methylphenidate, those with ADHD who were on MPH for 180 days (roughly half a year) or less had 77% fewer accidents, and those on MPH for over 180 days had 93% fewer accidents. This strong dose-response relationship is suggestive of a causal relationship, with MPH perhaps reducing impulsive behavior, particularly among young men with ADHD.
The team also conducted within-person analyses, comparing times when persons with ADHD were taking MPH with periods when they were not. These showed no effect within 30 days of use, rising to a 65%reduction in crashes within 60 to 90 days of use, which was barely outside the 95% confidence interval (p = .07), very likely because of "the extremely low incidence of transport accidence (i.e. 0.6%)enlarged the confidence interval."
The authors concluded, "All registration medical claim data came from the nationally-representative sample of NHI, minimizing the selection and recall bias. By excluding transport accidents before ADHD diagnosis, we have precluded the reverse association between ADHD and road traffic accidents as much as possible. The advantage of the between-subjects comparison was that we were able to examine the MPH effect in different dose groups. However, confounding by indication cannot be eliminated. For example, those with a severe degree of ADHD symptoms, an exhibition of risky behaviors, or comorbid with other psychiatric illnesses were more likely to be prescribed medication. Hence, we also performed within-subject comparisons to adjust for time-invariant factors."
Transport safety thus offers another compelling reason to treat ADHD symptoms. Methylphenidate in particular seems to be especially effective in reducing traffic fatalities and injuries.
Suicide is one of the most feared outcomes of any psychiatric condition. Although its association with depression is well known, a small but growing research literature shows that ADHD is also a risk factor for suicidality. Suicide is difficult to study. Because it is relatively rare, large samples of patients are needed to make definitive statements.
Studies of suicide and ADHD must also consider the possibility that medications might elevate that risk. For example, the FDA placed a black box warning on atomoxetine because that ADHD medication had been shown to increase suicidal risk in youth. A recent study of 37,936 patients with ADHD now provides much insight into these issues (Chen, Q., Sjolander, A., Runeson, B., D'Onofrio, B. M., Lichtenstein, P. & Larsson, H. (2014). Drug treatment for attention-deficit/hyperactivity disorder and suicidal behavior: a register-based study. BMJ 348, g3769.). In Sweden, such large studies are possible because researchers have computerized medical registers that describe the disorders and treatments of all people in Sweden. Among 37,936 patients with ADHD, 7019 suicide attempts or completed suicides occurred during 150,721 person-years of follow-up. This indicates that, in any given year, the risk for a suicidal event is about 5%. For ADHD patients, the risk for a suicide event is about 30% greater than for non-ADHD patients. Among the ADHD patients who attempted or completed suicide, the risk was increased for those who had also been diagnosed with a mood disorder, conduct disorder, substance abuse, or borderline personality. This is not surprising; the most serious and complicated cases of ADHD are those that have the greatest risk for suicidal events. The effects of the medication were less clear. The risk for suicide events was greater for ADHD patients who had been treated with non-stimulant medication compared with those who had not been treated with non-stimulant medication. A similar comparison showed no effect of stimulant medications. This first analysis suffers from the fact that the probability of receiving medication increases with the severity of the disorder. To address this problem, the researchers limited the analyses to ADHD patients who had some medication treatment and then compared suicidal risk between periods of medication treatment and periods of no medication treatment. This analysis found no increased risk for suicide from non-stimulant medications and, more importantly, found that for patients treated with stimulants, the risk for suicide was lower when they were taking stimulant medications. This protective effect of stimulant medication provides further evidence of the long-term effects of stimulant medications, which have also been shown to lower the risks for traffic accidents, criminality, smoking, and other substance use disorders.
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.
As populations grow, more children are growing up surrounded by traffic noise and polluted air. In most cities, these two factors tend to go hand-in-hand; yet, most previous research has examined these exposures separately. Many reviews focused on a single pollutant (such as fine particulate matter, PM2.5), or on a single developmental window, such as pregnancy or early childhood. Few have asked how noise and air pollution compare as risk factors, or how prenatal and postnatal exposures differ in their effects.
A new meta-analysis set out to address those gaps. It examined evidence on both environmental noise and several major air pollutants in relation to ADHD, compared exposures before versus after birth, and pooled data across countries and regions. Eligible studies involved children and adolescents under 18, used objective measures of environmental exposure, and assessed ADHD using either clinical diagnosis or standardized rating scales.
Noise
Nine studies, combining data from over 100,000 children and adolescents (all in European countries and Canada) found that high noise exposure was associated with 3% greater odds of ADHD. Prenatal noise exposure showed no effect; childhood exposure alone drove the association, at 4% greater odds. This is a negligible effect size that could easily reflect unmeasured confounding factors rather than a true causal relationship.
Nitrogen dioxide
Thirteen studies covering nearly one million children and adolescents in Europe, Canada, China, and South Korea found that nitrogen dioxide (NO₂) exposure was associated with 11% greater odds of ADHD. As with noise, prenatal exposure showed no independent effect. When the analysis was restricted to the five studies that used clinical diagnoses alone — generally considered the most reliable measure — the estimated odds rose to between 20% and 80% higher. The wide range reflects substantial variation across studies.
Pollutants with no significant effect
Four studies (97,500 participants) examining nitric oxide (NO), three studies (over 63,000 participants) on ozone, and three studies (over 28,000 participants) on sulfur dioxide found no significant associations with ADHD.
Particulate matter
The strongest associations emerged for particulate matter. Twelve studies involving nearly 160,000 participants in China, the US, Canada, and Europe found that exposure to fine particles (PM2.5, 2.5 microns in diameter) was associated with 30% greater odds of ADHD. Ten studies covering more than a quarter of a million participants in India, China, South Korea, and Europe found that coarser particles (PM10, 10 microns) were associated with 50% greater odds. In both cases, prenatal exposure showed no association, which is consistent with the fact that fetuses do not breathe air through developed lungs. When restricted to clinically diagnosed ADHD, PM2.5 was associated with roughly 50% greater odds, and PM10 with more than double the odds.
The Results
Across all exposures examined, particulate matter showed the clearest and strongest associations with ADHD, followed by nitrogen dioxide. Noise reached statistical significance but at a trivially small effect size. Nitric oxide, ozone, and sulfur dioxide showed no significant associations.
The authors found no evidence of publication bias which strengthens confidence in the overall pattern. However, there was marked heterogeneity across individual studies: results varied considerably, which urges caution in treating any single estimate as definitive. These are associations, not proven causal relationships, and the possibility that unmeasured factors explain part of the signal cannot be ruled out.
The Background:
Over the past two decades, diagnostic rates for adult ADHD have roughly doubled, and stimulant prescriptions in the United States skyrocketed by more than 50% between 2012 and 2023, particularly among girls and women. While these medications help many individuals manage their symptoms, a landmark 2026 article published in European Neuropsychopharmacology tackles an important question that is rarely discussed: When should doctors and patients consider stopping them?
The Discussion:
To answer this, the American Society of Clinical Psychopharmacology (ASCP) gathered a task force of 45 international experts spanning 12 countries. Through a rigorous evaluation process, they reached an overwhelming agreement on a framework for "deprescribing", the planned, supervised reduction or cessation of a medication. Here are the core insights from these ground-breaking guidelines and what they mean for adults navigating long-term ADHD treatment.
When the Treatment Isn’t Yielding Benefits
One of the most straightforward reasons to consider stopping a stimulant is if it simply isn’t doing its job. The task force agreed that if a patient does not experience an optimal response, measured by actual symptom reduction, improved daily functioning, and a better quality of life, even after trying a high, optimized dose, it may be time to step back and look at alternative options.
Sometimes, the issue goes back to the initial evaluation. The criteria for diagnosing ADHD have expanded over the years, and brief psychiatric evaluations can occasionally lead to diagnostic inaccuracies. If a thorough reevaluation reveals that the original ADHD diagnosis was incorrect, the expert consensus is clear: stimulant deprescribing is appropriate unless another stimulant-responsive condition is evident. Furthermore, if a patient develops a persistent tolerance to the drug that cannot be resolved by safe dose adjustments, a temporary taper or drug holiday may be recommended.
When the Risks to Health Outweigh the Rewards
Our bodies and health needs naturally shift over time, meaning a medication that worked safely years ago might pose a threat to your health today. The experts concluded that deprescribing should be heavily considered if stimulants exacerbate a concurrent medical or psychiatric illness. For example, although rare, stimulants can unintentionally trigger mania or psychosis in adults with unstable or unrecognized comorbid bipolar disorder.
Physical health developments are equally critical. If an adult develops a newly arising or unstable cardiovascular condition, such as a cardiac arrhythmia, ischemia, or cardiomyopathy, the risk-benefit balance changes dramatically. Additionally, if severe side effects occur that cannot be managed by reducing the dosage, or if dangerous new drug-drug interactions emerge, stopping the medication under medical supervision protects the patient's long-term well-being.
Addressing Misuse and the Complex Role of Cannabis
Because stimulant medications target brain reward and wakefulness circuitry, they can foster a propensity for misuse. Studies indicate that more than 1 in 5 adults prescribed stimulants have misused them, and 1 in 6 have diverted their medication to others. The task force emphasizes that deprescribing is warranted if a patient persistently takes doses higher than prescribed against medical advice, uses the medication purely for unauthorized performance enhancement, or has an untreated, coexisting substance use disorder.
And what about cannabis? This topic sparked the most debate among the experts, falling just short of an official consensus with 71% agreement that regular cannabis use alone shouldn't automatically trigger a stimulant stoppage. Recognizing the complexity, such as how chronic cannabis use can overlap with ADHD executive function deficits, the task force proposed a structured monitoring approach instead of an immediate cutoff. Clinicians are encouraged to track the patient every 1 to 3 months using standardized symptom tools and random urine drug screens to verify whether cannabis use is actively neutralizing the stimulant's therapeutic benefits.
The Path Forward: Safe Tapering and Lifestyle Support
If you and your doctor decide that stopping a stimulant is the right path, it shouldn’t happen overnight. The task force strongly recommends that medications be gradually tapered off at a rate tailored to the individual to minimize potential disruptions and distinguish between transient withdrawal and a true return of ADHD symptoms.
Crucially, stopping a medication doesn't mean stopping treatment. The experts highlight that the success of any deprescribing plan is significantly enhanced when patients focus on optimizing modifiable lifestyle factors. Prioritizing sleep hygiene, staying physically active, and implementing structured behavioral strategies can support executive functioning and help sustain your cognitive gains even as the medication is reduced or eliminated.
The Takeaway:
The decision to continue or stop an ADHD medication is a deeply personal one that requires balancing real-world efficacy, safety, and individual health changes. These new consensus recommendations provide an essential roadmap to help adults navigate their long-term mental health journeys safely and effectively.
Are you or a loved one currently evaluating your long-term relationship with ADHD medication? Consider scheduling a check-in with your healthcare provider to discuss whether your current treatment plan still perfectly matches your health needs today.
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