Swedish Study Reveals ADHD’s Impact on Criminal Convictions—and How Medication Reduces Risk

ADHD has long been associated with higher rates of criminal behavior, but most studies have relied heavily on self-reported data and small, non-representative samples. A new Swedish study addresses these limitations, providing a more comprehensive and reliable picture using data from nationwide registers. It sheds light on the role of ADHD medication in reducing the risk of criminal convictions, offering insights for clinicians, policymakers, and families.

Previous Research: The Denmark Comparison

Earlier research, such as a 2019 Danish study, found that ADHD diagnosed in children and adolescents ages 4 to 15 was associated with a 1.6-fold increased risk of future criminal conviction. However, these findings were limited by a smaller sample size and a focus on just one nation’s context. Like Denmark, Sweden’s single-payer universal healthcare system allows for the collection of extensive data on health and crime records, providing an ideal environment for large-scale, population-based research.

Swedish Study Design: A Robust Approach

To investigate ADHD’s connection to criminal behavior, the Swedish research team analyzed records from a cohort of 1,646,645 individuals born between 1986 and 1997. They excluded those who died or emigrated before age 15 (the age of criminal responsibility in Sweden) and those who immigrated to Sweden, resulting in a final study group of 1,235,939 individuals. Slightly more than half of the cohort was male.

ADHD diagnoses were based on clinical records and prescriptions for approved ADHD medications, while criminal convictions—both violent and nonviolent—were identified using Sweden’s National Crime Register, covering the years 2001 to 2013. The study adjusted for various potential confounding factors, including sex, birth year, parental education, and other psychiatric conditions. They also used the Swedish Multi-Generation Register to control for unmeasured familial factors to compare outcomes among full siblings.

Key Findings: ADHD and Criminality

The study found that ADHD is strongly associated with increased rates of criminal convictions. Compared to individuals without ADHD, those with an ADHD diagnosis were roughly:

  • Four times more likely to be convicted of a violent crime.
  • Twice as likely to be convicted of a nonviolent crime.

Interestingly, when comparing conviction rates among males and females with ADHD, the rates of nonviolent convictions were similar, but females with ADHD were about 25% more likely to be convicted of a violent crime than males with ADHD.

The Role of Medication: A Significant Moderating Factor

The research also highlighted the importance of ADHD medication in reducing criminal behavior. When individuals with ADHD who were taking medication were excluded from the analysis, the data showed significantly higher rates of criminal convictions:

  • Unmedicated males with ADHD had a 50% higher rate of violent convictions and more than double the rate of nonviolent convictions compared to their typically developing peers.
  • Unmedicated females with ADHD faced even greater risks, with nearly triple the rate of violent convictions and quadruple the rate of nonviolent convictions.

These findings suggest that ADHD medications can significantly reduce the risk of both violent and nonviolent criminal behavior in individuals with ADHD, emphasizing the value of pharmacological treatment for those with the condition.

Clinical Implications: Medication as a Risk-Reducing Strategy

The researchers concluded that “ADHD is a strong risk factor for both violent and non‐violent criminal convictions in males and females even after adjustments for psychiatric comorbidities and unmeasured familial factors.” The study also found that untreated ADHD poses a particularly high risk for criminal behavior, highlighting the protective role of medication.

These findings are clinically relevant for several reasons. First, they reinforce the importance of ensuring that individuals with ADHD have access to effective treatment options, especially during the transition from adolescence into adulthood, which is statistically a period of higher risk for criminal behavior. Additionally, the study provides critical data for shaping public policy and interventions aimed at supporting individuals with ADHD, with a focus on reducing criminality through proper management of the disorder.

Conclusion:

This study offers new insights into the complex relationship between ADHD, medication, and criminal behavior, emphasizing the crucial role of treatment in mitigating risks. It provides a compelling case for prioritizing access to ADHD medication as part of a broader strategy for supporting those with ADHD.

Anna-Karin Ångström, Anneli Andersson, Miguel Garcia-Argibay, Zheng Chang, Paul Lichtenstein, Brian M. D’Onofrio, Catherine Tuvblad, Laura Ghirardi, and Henrik Larsson, “Criminal convictions in males and females diagnosed with attention deficit hyperactivity disorder: A Swedish national registry study,” JCPP Advances (2024), e12217, https://doi.org/10.1002/jcv2.12217

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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

Direct medical costs of adult incident ADHD in Germany

Direct medical costs of adult incident ADHD in Germany

A team of German researchers explored five million member records from a database that tracks more than sixty nationwide statutory health insurance programs. The database closely tracks the characteristics of the overall German population.

This was a longitudinal cohort study, tracking individuals first diagnosed with adult ADHD between 2013 and 2017. Anyone who was not continuously insured during this period was excluded, as were those who died, plus anyone older than 55 to prevent bias from high morbidity in the top age brackets.

The study team used the database to add up direct healthcare costs, including inpatient care, outpatient care, psychotherapy, medical aids and remedies, medication, and sickness benefits. In Germany, sickness benefits kick in after more than six weeks of continuous inability to work.

The study tracked data within a window extending both four years back and four years forward from the initial adult ADHD diagnosis.

The resulting study cohort consisted of 2,380 persons between 18 and 55, initially diagnosed with ADHD at an average age of 35. Sixty percent were male.

One-third were prescribed ADHD medication upon diagnosis. Four years later, only one-eighth were still on medication.

Almost two-thirds received psychotherapy, dropping to under a third in succeeding years.

During the year following diagnosis, average healthcare costs totaled about €4,000 per individual. For those who initiated ADHD medication, the average cost was just over €5,400, and for those who did not it was almost €3,500.

The authors concluded, "An important finding of the present investigation is that in the year of initial diagnosis, less than one-third of individuals received any prescription of ADHD-specific medication, and only a fourth got at least two prescriptions. At the same time, almost two-thirds of individuals received psychotherapy in the year of ADHD[adult ADHD] diagnosis. In about one-third of individuals, psychotherapy had been initiated already before a diagnosis of ADHD, presumably for treatment of comorbid disorders. ... In current German guidelines, ADHD-specific medication is recommended as the first choice ... Apparently, despite the vast body of evidence for the beneficial effects of ADHD-specific medication, at least in the short-term, and in contrast to the recommendations of previous and current guidelines, stimulant medication is only reluctantly prescribed in newly identified adults with ADHD. ... Overall, our findings suggest that significant deficiencies may currently exist concerning the reality of healthcare for ADHD in Germany, and that guideline recommendations are not yet comprehensively implemented in everyday routine care."

December 7, 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

Swedish Nationwide Population Study: Newborn Seizures Double Risk of ADHD

The first few weeks of life are the time when babies are most vulnerable to seizures (known as neonatal seizures). This is partly because of events that can occur during birth, and partly because the newborn brain is naturally in a more excitable state than a mature brain, making it more prone to seizure activity. 

Seizures affect roughly 1 to 3 in every 1,000 full-term babies born, and the rate is considerably higher in premature babies, at around 11 to 14 per 1,000. In most cases, seizures at this age are triggered by a specific event or injury affecting the brain. In full-term newborns, the most common cause is a condition called hypoxic-ischemic encephalopathy (HIE), which occurs when the brain is deprived of adequate oxygen and blood flow around the time of birth. Other causes include genetic or metabolic conditions, stroke, bleeding in the brain, and structural abnormalities in how the brain developed. In very premature babies, bleeding into the fluid-filled spaces of the brain (known as intraventricular hemorrhage) is the leading culprit. 

Diagnosing seizures in newborns is tricky because many normal or abnormal movements and behaviors in this age group can look like seizures without actually being them. For this reason, monitoring the baby’s brain activity using an electroencephalogram (EEG) – a test that records electrical signals in the brain – is essential to confirm whether a seizure is truly occurring. 

Sweden’s single-payer health system provides universal coverage, with national registers linking healthcare and population data. Researchers tracked infants with EEG/aEEG-confirmed seizures born between 2009 and 2020 and compared them to controls without neonatal seizures. 

Altogether, 1062 infants with neonatal seizures were matched with 5310 controls. 

The team adjusted for birth, mode of delivery, sex, birth weight, and Apgar scores – quick, standardized assessments used to evaluate newborns’ health minutes after birth. 

With these adjustments, infants who had neonatal seizures were twice as likely to subsequently be diagnosed with ADHD and three times as likely to be subsequently diagnosed with autism spectrum disorder.  

The authors emphasized that because the study was observational, it cannot demonstrate a direct cause-and-effect relationship between neonatal seizures and outcomes. Factors like seizure frequency, genetics, and socioeconomic status are thought to significantly impact the prognosis of affected children, but these could not be included in this study due to data limitations. 

March 18, 2026

Meta-analysis Finds Small to Moderate Benefits of Single Exercise Sessions for Adult ADHD

Background: 

There are currently few long-term treatment options for adult ADHD. Psychostimulants can help reduce symptoms, but their benefits rely on availability, continued use, and are not easily tolerated by some. Cognitive-behavioral therapies have also proven to be helpful, but access is limited because they must be provided by trained specialists. These challenges highlight the need to explore alternative interventions that could provide cognitive and behavioral improvements with fewer side effects. 

Exercise has shown potential as a nonclinical intervention for ADHD. Previous research indicates that physical activity can increase cortical volume, enhance brain activation, and boost connectivity in cognitive regions, as well as raise dopamine and norepinephrine levels – effects similar to psychostimulants. Research in children and teens with ADHD has found that both regular exercise programs and even single workout sessions can improve executive functions (mental skills like planning and self-control) and reduce core ADHD symptoms. But whether exercise helps adults with ADHD has remained an open question. 

Study:

A Chinese sports medicine research team set out to answer this by reviewing all available peer-reviewed studies on exercise and adult ADHD. They found so few studies on regular exercise programs – only four total, and three of those were small pilot studies just testing whether the approach was feasible – that they couldn’t draw firm conclusions about long-term exercise interventions. 

However, they were able to analyze four moderate-to-high-quality studies involving 152 adults with ADHD that tested single exercise sessions. The combined results showed moderate improvements in inhibitory control (the ability to resist impulses and stay focused). Adults not taking medication showed large improvements.  

When they looked at four studies involving 170 adults, they found small but consistent improvements in core ADHD symptoms after single exercise sessions. There was little to no variation (heterogeneity) in individual study outcomes, and no sign of publication bias. 

Results:

The team concluded, “Overall, these findings offer preliminary evidence on the potential role of exercise as a helpful strategy in the management of adult ADHD,” but cautioned that more well-designed randomized controlled trials are needed to determine the efficacy of both acute and chronic exercise interventions for adult ADHD, with particular emphasis placed on determining the best “prescription” for exercise – what type, how intense, and how often. 

They also noted that most existing research has focused narrowly on attention and impulse control, while other important mental abilities like working memory and mental flexibility remain largely unexplored. 

Take-Away

The takeaway here is practical and accessible: you don't need a long-term fitness program to get a cognitive bump from exercise if you have ADHD. Even a single session appears to help — particularly with impulse control. While the research base is still thin and we don't yet know the ideal exercise "prescription," the risk-benefit calculation is hard to argue with. For adults with ADHD who can't access medication or therapy, or who simply want an additional tool, breaking a sweat may be worth building into the routine.

Meta-analysis Finds People with ADHD Twice as Likely to Self-harm

Background: 

Non-suicidal self-injury (NSSI) means intentionally hurting yourself without trying to end your life. Common examples include cutting, scratching, or burning yourself. This behavior is most common in teenagers, affecting 13-20% of adolescents. It’s also called self-harm or deliberate self-injury. 

Young people who struggle with managing emotions, act impulsively, or have mental health conditions like depression are more likely to self-harm. 

Because ADHD involves impulsivity and often occurs alongside emotional difficulties, researchers have suspected a link between ADHD and self-injury. However, previous studies have tended to be small, unrepresentative, and inconsistent, making it hard to draw clear conclusions. 

The Study: 

Researchers combined results from 14 different studies involving nearly 30,000 people to get a clearer picture. They looked at children, teenagers, and adults with ADHD from various settings—including hospitals, community programs, and general population studies. 

To be included, studies had to confirm ADHD diagnosis through professional evaluation or validated testing methods. 

Key findings 

  • About 1 in 4 people with ADHD (27%) have engaged in self-injury. This rate was similar for adults (25%) and teenagers (28%).
  • People with ADHD had more than twice the odds (2.25 times higher) of self-injury compared to people without ADHD 
  • Girls and women with ADHD were at highest risk—they had four times higher rates of self-injury than boys and men with ADHD 

Conclusion: 

The researchers concluded that roughly one in four people with ADHD have engaged in non-suicidal self-harm. The findings suggest that ADHD and self-harm share overlapping vulnerabilities. 

Overall, this meta-analysis strengthens evidence that people with ADHD face a significantly elevated risk of non-suicidal self-injury, likely reflecting overlapping challenges with impulsivity, emotional regulation, and co-occurring mental health conditions. Importantly, this does not mean self-harm is inevitable in ADHD. It does, however, highlight the need for early screening, supportive environments, and targeted mental-health care to help reduce risk and support healthier coping strategies.

March 5, 2026