Sign In
International
Media release
From:
ADHD medication linked to reduced risk of suicide, drug abuse, transport accidents and criminal behaviour
Findings should help inform clinical practice and the debate on ADHD drug treatment
Drug treatment for people with newly diagnosed attention deficit hyperactivity disorder (ADHD) is associated with significantly reduced risks of suicidal behaviours, substance misuse, transport accidents, and criminality, finds a study published by The BMJ today.
The researchers say this is the first study of its kind to show beneficial effects of ADHD drug treatment on broader clinical outcomes for all ADHD patients and should help inform clinical practice.
ADHD affects around 5% of children and 2.5% of adults worldwide and is associated with adverse outcomes including suicidal behaviours, substance misuse, accidental injuries, transport accidents and criminality.
Although randomised trials have shown that ADHD medication alleviates core symptoms, evidence of its effects on these broader clinical outcomes are more limited.
To address this knowledge gap, researchers drew on data from Swedish national registers (2007-2020) to examine the effects of ADHD drug treatment in 148,581 individuals aged 6-64 years with a new diagnosis of ADHD.
Using a technique called target trial emulation, which applies the design principles of randomised trials to observational data, they assessed first and recurrent events for five outcomes (suicidal behaviours, substance misuse, accidental injuries, transport accidents, and criminality) over two years after diagnosis.
Of the 148,581 individuals with ADHD (average age 17 years; 41% female), 84,282 (57%) started drug treatment for ADHD, with methylphenidate being the most commonly prescribed (88.4%).
After accounting for factors including age, sex, education level, psychiatric diagnoses and medical history, ADHD medication was associated with reduced rates of a first occurrence of four of the five outcomes: a 17% reduction for suicidal behaviour, 15% for substance misuse, 12% for transport accidents, and 13% for criminality.
The reduction was not statistically significant for a first-time accidental injury (88.5 v 90 per 1000 person years).
However, amongst people with recurrent events, the rate reductions associated with ADHD medication were seen for all five outcomes: a 15% reduction for suicidal attempts, 25% for substance misuse, 4% for accidental injuries, 16% for transport accidents, and 25% for criminality.
Possible explanations include reduced impulsivity, which might lower criminality by curbing aggressive behaviour, and enhanced attention, which might decrease the risk of transport accidents by minimising distractions, suggest the authors.
They acknowledge several limitations, such as being unable to assess data on non-drug treatments or the impact of drug dosage. And while target trial emulation is one of the most rigorous approaches for analysing observational data, they can’t rule out the possibility that other factors, such as ADHD severity, genetic predispositions, and lifestyle factors, may have affected their results, so no definitive causal conclusions can be drawn.
However, this was a large study based on national registry data and findings were similar after further sensitivity analyses, suggesting they are relevant to people with ADHD in real-world clinical settings.
As such, they conclude: “These results provide evidence on the effects of ADHD drug treatment on important health related and social outcomes that should inform clinical practice and the debate on the drug treatment of ADHD.”
Expert Reaction
These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.
Alison (Sally) Poulton is a Senior Lecturer from the Sydney Medical School Nepean at The University of Sydney, and a Board advisor to ADHD Australia
In this cohort of young adults, treatment of ADHD with stimulant medication was associated with a reduction in important real-life events such as suicide attempts, criminality, traffic accidents and substance use. These findings emphasise the importance of investing in ADHD services for young people and making sure that treatment is accessible and affordable.
Professor Jon Jureidini is a Child Psychiatrist and Research Leader in Critical and Ethical Mental Health from the School of Medicine and Robinson Research Institute at The University of Adelaide
These appear to be encouraging findings for a population that is carefully diagnosed.
The main concern is that the authors do not take account of the healthy user bias - only patients compliant for two years are included in the medicated arm. Patients who comply with treatment, especially for such a long period, are not representative of the medicated population. They and their families are more likely to engage in a broad spectrum of behaviours consistent with a healthy lifestyle. Outcomes for those who were non-compliant should also have been analysed, even if only as a secondary analysis to acknowledge the possibility of healthy user bias.
We need to always be wary of pro-medication findings where authors who are heavily linked to pharma (see CoI in the paper).
Dr Jack Janetzki is a Lecturer in Pharmacy and Pharmacology at the University of South Australia
This study found that ADHD medicines are linked to reduced risks of suicidal behaviours, substance misuse, transport accidents, and criminal convictions. The use of ADHD medicines also appeared to reduce the rate of recurrent events too.
This study is significant because it moves beyond symptom control to show how ADHD medications may improve safety and social outcomes. As a health professional, these findings appear to be impactful for the broader ADHD community. The authors provide population-level evidence that supports the broader benefits of ADHD treatment, especially for those people at higher risk.
For Australians, this research is timely. ADHD medication use is rising nationally. These findings offer reassurance to families and clinicians, highlighting the potential of medication to reduce harm and improve lives beyond symptom control. This study highlights the broader public health value of ADHD medications and reinforces the need for inclusive, long-term studies that reflect everyday clinical practice, particularly in the Australian context.
These findings should inform future policy, clinical guidelines, and public discourse around ADHD treatment. It was pleasing to see that the authors included the comparison between stimulants and non-stimulant ADHD medicines which may influence risk of the investigated outcomes. Further comparison between ADHD medicines and the likelihood of these risks would also be valuable as well as stratification by ADHD subtype.
Professor Rob Hester is from the Melbourne School of Psychological Sciences at the University of Melbourne
ADHD, with its core symptom of impulsivity, increases our risk for substance misuse and dependence. Due to the short-term follow-up of clinical trials, it has been unclear whether stimulant medications for ADHD reduce this risk, or inadvertently increase it (particularly for medication misuse). The Zhang et al. study followed up nearly 150,000 Swedish people (children and adults) diagnosed with ADHD since 2007, finding that medication significantly reduced the incidence of substance misuse, with the effect increasing when comparing stimulant to non-stimulant ADHD medication prescription. The current study addresses many of the limitations of past research on ADHD-related substance use risk, with their extended follow-up and comprehensive population-based inclusion, though is limited by the typical confound that upwards of 60% of people do not seek treatment for substance misuse.
Stuart Kinner is a Professor of Health Equity in the School of Population Health, and Head of the Justice Health Group, at Curtin University, and Head of the Justice Health Group at Murdoch Children's Research Institute
This is a landmark piece of research, convincingly demonstrating the diffuse benefits of ADHD diagnosis and treatment. Timely drug treatment led to significant reductions in suicidal behaviour, substance use, transport accidents, and criminality. These findings confirm what many already know: failure to diagnose and treat ADHD can lead to self-medication with alcohol or other drugs, poor mental health, injury, and incarceration. Too many people with undiagnosed ADHD end up in the criminal justice system, where their condition may remain undiagnosed and untreated. It is estimated that around one in four people in prisons and youth detention centres have ADHD, although this is frequently undiagnosed.
There are two key messages: (1) Greater investment in ADHD screening for children and adolescents in schools could reduce the number of young people – particularly vulnerable and marginalised young people – who end up self-medicating their ADHD with substances, and living lives distinguished by poor mental health, injury and – far too often – criminalisation of neurodivergence. (2) For people who end up in the criminal justice system, screening for ADHD could lead to better health outcomes for those diagnosed and treated, and reduce rates of reoffending. That’s a win for public health, and a win for public safety.
Professor Adam Guastella is the Michael Crouch Chair in Child and Youth Mental Health at Children’s Hospital Westmead Clinical School and the University of Sydney
It's important to understand the risks and benefits of ADHD medication use, to give people informed choices about what they use to support themselves or their children. People can spend a long time seeking a diagnosis and discussing treatment, and the investment of time needs to be worth it and evidence based. So it's important to understand the breadth of possible impact.
Its always helpful to know if medications can impact daily life beyond reducing reducing symptoms. This information is also important for government, to help policy makers understand the potential benefits of treatment for broader society, such as mental health or criminal outcomes.
This study shows that individuals who started ADHD medication showed a reduction in suicidality, substance misuse and criminality. Such benefits have been shown repeatedly in previous studies, but the large sample size, use of a national registry, and more sophisticated analysis give greater confidence in these results that findings aren't explained by something else other than medication use. This is one of a number of studies that show the benefits of stimulant medication for people with ADHD and their life. People should know that if ADHD medications work for them and their child, that there will likely be many other positive impacts on life from treatment. Such effects will not work for everyone and there is still a need to understand why many individuals benefit from ADHD medication and some do not. Finally, even though the study was rigorous in its design, one cannot rule out that other unaccounted factors could be associated with these effects and the study focused on adults.
Dr Stephen Bright is Senior Lecturer of Addiction within the School of Medical and Health Sciences at Edith Cowan University and a Director of Psychedelic Science in Science & Medicine Ltd.
"This research provides further evidence that stimulant medication treatments for ADHD can be life changing, reducing the risk of individuals experiencing a motor vehicle accident and drug-related harms, in addition to reducing the likelihood that they will engage in criminal behaviour and suicide. Yet it is very difficult for many Australians to access a paediatrician or psychiatrist who is able to commence stimulant medication treatments where appropriate due to extensive waitlists, in addition to financial and regulatory obstacles. As such, a number of people with undiagnosed ADHD continue to present for help with their drug use at alcohol and other drug treatment services, while others remain in prison.
While there are concerns about the over-prescribing of stimulant medications in Australia and the potential diversion of stimulant medications for non-medical use, it is important that we find the right balance between protecting the community from diverted medications and the right of people with ADHD to access a gold standard treatment so that they are able to thrive and be productive members of society."
