National Birth Cohort Finds Young Adults with ADHD Over-represented in Criminal Justice System

Using Statistics New Zealand’s Integrated Data Infrastructure (IDI), a large database of linked de-identified administrative and survey data about people and households, a local study team examined a three-year birth cohort (mid-1992 through mid-1995) totaling 149,076 persons.

The team assessed the presence of ADHD within this cohort through diagnosis codes and inference from medication dispensing, where there was at least one code relating to an ADHD diagnosis in the medication datasets. This subgroup consisted of 3,975 persons.

Next, they related this information to criminal justice system interactions of increasing severity, starting with police proceedings, and continuing with court charges, court convictions, and incarcerations. These interactions were tracked during an eight-year period from participants’ 17th birthday through their 25th birthday.

In this same period the team also tracked types of offenses: against people; against property; against organizations, government, and community; and violent offenses.

In all cases, the study team adjusted for gender, ethnicity, deprivation, and area of residence as potential confounders. 

With these adjustments, young adults with ADHD were over twice as likely as their typically developing peers to be proceeded against by police, to be charged with an offense, and to be convicted. They were almost five times as likely to be incarcerated. 

With the same adjustments, young adults with ADHD were over twice as likely as their typically developing peers to be convicted of offenses against organizations, government, and community. They were almost three times as likely to be convicted of crimes against persons, and over three and a half times more likely to be convicted of either violent offenses or offenses against property.

The authors noted, “The greater effect size for incarceration observed in our study may be due to the lack of control for comorbid conditions such as CD [conduct disorder], which are known criminogenic risk factors.” 

They also noted, “The sharp increase in the risk of incarceration observed may also signal differences in the NZ justice system’s approach to ADHD, which may be less responsive to the condition than other nations, particularly the steps in the justice system between conviction and sentence. This would suggest that the UNCRPD [United Nations Convention on the Rights of Persons with Disabilities] obligations of equal recognition before the law and the elimination of discrimination on the basis of disability are not being met for individuals with ADHD in NZ.”

They concluded, “Our findings revealed that not only were individuals with ADHD overrepresented at all stages of the CJS [criminal justice system] and offense types examined, there was also a pattern of increasing risk for CJS interactions as these individuals moved through the system. These results highlight the importance of early identification and responsivity to ADHD within the CJS and suggest that the NZ justice system may require changes to both of these areas to ensure that young individuals with ADHD receive equitable access to, and treatment within, the CJS.”

Francesca Anns, Stephanie D’Souza, Conrad MacCormick, Brigit Mirfin-Veitch, Betony Clasby, Nathan Hughes, Warren Forster, Eden Tuisaula, and Nicholas Bowden, “Risk of Criminal Justice System Interactions in Young Adults with Attention-Deficit/Hyperactivity Disorder: Findings From a National Birth Cohort,” Journal of Attention Disorders (2023), 1-11, https://doi.org/10.1177/10870547231177469.

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Nationwide population study in Denmark finds children and adolescents with ADHD more than twice as likely to suffer criminal violence

Denmark Population Study Finds Children and Adolescents with ADHD More than Likely to Suffer Criminal Violence

Children with disabilities are known to be at heightened risk of violence compared to their non-disabled peers. To what extent does this hold true for ADHD?

Denmark has a single-payer health insurance system through which health data about virtually the entire population can be cross-referenced with population, crime, welfare, and other registers through unique individual person numbers.

A Danish study team accessed national registers to examine the relationship between ADHD and criminal victimhood among nine yearly birth cohorts totaling more than 570,000 children and adolescents. 

Of these, 557,521, among them 12,040 with ADHD, were not reported as being exposed to violence, and 12,830, among which 1,179 with ADHD, were exposed to violence.

From the raw data, children and adolescents with ADHD were more than four times as likely to be exposed to violence than their typically developing peers.

The team then adjusted for other disabilities, family risk factors, gender, birth year, and ethnic background.

With these confounders out of the way, children and adolescents with ADHD remained more than twice as likely to be exposed to violence than their typically developing peers.

To place this outcome in further perspective:

  • Brain injuries increased the odds of being exposed to violence by over 75% relative to typically developing peers.
  • Physical and speech disabilities raised the odds by a bit over 35%.
  • Intellectual and sensory disabilities, dyslexia, and congenital malformations had no effect. 
  • Epilepsy reduced the odds of being exposed to violence by just under 20%, and autistic spectrum disorder by just over 25%.

Certain family risk factors further aggravated the odds:

  • Violence in the family by more than 2.5-fold.
  • Out-of-home care and breakup of parental relationship by more than 75%.

Perhaps surprisingly, substance abuse by family members had no effect whatsoever after adjusting for confounders.

January 24, 2024

Nationwide population study suggests ADHD medication may reduce child abuse

Nationwide Population Study Suggests ADHD Medication May Reduce Child Abuse

Child abuse includes any of the following inflicted on a minor under 18 years old: physical or emotional harm, sexual abuse, or neglect.

It is known to be associated with environmental factors such as poverty, parents or neighbors with a history of violence, and gender inequality.

Chronic mental disorders in minors are also associated with child abuse. To what extent, if any, might that be true of ADHD?

Taiwan has a single-payer national health insurance system that covers more than 99.6% of all residents, enabling nationwide population studies.

A local research team used data from almost two million Taiwanese in their country’s National Health Insurance Research Database (NHIRD) spanning 15 years (2000-2015) to carry out a matched-cohort study. 

All diagnoses of ADHD were made by board-certified specialists such as psychiatrists, pediatricians, neurologists, or physiatrists with a specialty in child and adolescent development.

3,540 children and adolescents between 6 and 18 years old with a diagnosis of ADHD were matched on a one-to-three basis with 10,620 peers from the NHIRD without an ADHD diagnosis.

The team adjusted for age, gender, location of residence (Northern, Central, Southern, and Eastern Taiwan), urbanization level of residence, level of hospitals as medical centers, and monthly insured premium. They further adjusted for comorbid conditions: intellectual disability, autistic disorder/pervasive developmental disorder, conduct disorder (CD)/oppositional defiant disorder (ODD), other developmental disorders, childhood emotional disorder, Tourette syndrome/tics disorders, and involuntary urination and defecation.

Overall, children and adolescents with an ADHD diagnosis were 1.8 times as likely to be abused as those without an ADHD diagnosis.

Unmedicated children and adolescents with an ADHD diagnosis were three times more likely to be abused. ADHD medication cut that risk in half.

That held true whether the medication used was methylphenidate or atomoxetine. Methylphenidate appeared to be slightly more effective than atomoxetine, and the combination of methylphenidate and atomoxetine slightly more effective yet, but these differences were not statistically significant.

The team concluded, “The results support that pharmacotherapy may attenuate the risk of child abuse in ADHD patients.”

March 5, 2024

Assessing Co-occuring Disorders in Relatives of Those With ADHD

Taiwan Population Study Assesses Comorbidity of Psychiatric Disorders among First-degree Relatives of Those with ADHD

Taiwan's National Health Insurance program is a single-payer system that covers 99.6% of the island's 23 million residents. It includes family relationships.

This enabled a Taiwanese study team to examine the comorbidity of psychiatric disorders among close relatives in the entire population over eleven years, beginning at the start of 2001 and concluding at the end of2011.

For greater certainty of diagnosis, only persons twice diagnosed with the same psychiatric disorder were included as index individuals. There were 431,887 index patients, 152,443 of whom were ADHD index patients.

These index patients were then compared with all of their first-degree relatives (FDRs): parents, children, siblings, and twins. This produced 1,017,430 patient-FDR pairs, of which 401,301 were ADHD patient-FDR pairs.

Next, four controls were matched by age, gender, and type relative to each case, resulting in 4,069,720 control pairs.

After adjusting for age, gender, urbanization, and income level, ADHD patients were seven times more likely than controls to have first-degree relatives with ADHD. They were also seven times more likely to have FDRs with major depressive disorder, four times more likely to have FDRs with autism spectrum disorder, twice as likely to have FDRs with bipolar disorder, and 80%more likely to have FDRs with schizophrenia.

February 3, 2023

Meta-analysis: Cognitive Behavioral Therapy for Adult ADHD

A recent meta-analysis examined how well cognitive behavioral therapy (CBT) improves not just symptoms, but everyday functioning and quality of life in adults with ADHD. 

The Background:

ADHD in adults affects far more than attention or impulsivity. It often disrupts key areas of life: 

  • Education: Adults with ADHD tend to have lower GPAs, use fewer effective study strategies, achieve less academically, and are more likely to drop out.  
  • Work: They are more likely to experience job instability, including underperformance, unemployment, being fired, or frequent job changes.  
  • Social life: They often report smaller social networks, fewer close relationships, greater loneliness, and difficulty maintaining friendships or intimacy. Importantly, stronger social networks can help buffer (reduce) the impact of ADHD symptoms on daily life.  
  • Quality of life: Overall well-being is typically lower, affecting not only individuals but also their families and close relationships.

These broad impacts highlight a key issue: reducing symptoms does not automatically translate into better day-to-day functioning. 

CBT is a structured, skills-based therapy that helps people: 

  • Identify and challenge unhelpful thought patterns  
  • Reduce avoidance behaviors  
  • Build practical strategies for managing time, organization, and other executive functions (the mental skills used to plan, focus, and follow through)  

While both medication (especially stimulants) and CBT improve core ADHD symptoms, CBT is particularly aimed at improving real-world functioning. 

The Study:

The researchers analyzed studies involving adults diagnosed with ADHD (or showing clinically significant symptoms). They included: 

  • Randomized controlled trials (RCTs): studies comparing CBT to another treatment or to no treatment  
  • Within-subject studies: studies measuring change in the same individuals before and after CBT  

They focused specifically on outcomes beyond symptoms: 

  • Occupational functioning (work performance)  
  • Global functional impairment (overall daily functioning)  
  • Social relationships  
  • Academic functioning  
  • Quality of life  

The Results:

1.  Strongest Effects: Occupational functioning
CBT showed consistently strong improvements in work-related functioning compared to control groups, both immediately after treatment and at follow-up. This was the most robust finding across domains. 

2. Moderate Improvement: Global Functional Impairment
CBT led to moderate improvements in overall daily functioning, with some evidence that gains persist over time. In studies tracking individuals over time, improvements were even stronger at follow-up. 

3. Modest Gains: Social Relationships
CBT produced small to moderate improvements in social functioning. Benefits were present both after treatment and at follow-up, but were less pronounced than in work-related outcomes. 

4. Limited Effects: Academic Functioning
There were moderate short-term gains when CBT was compared to control groups, but these did not persist at follow-up. Within-subject studies showed only small improvements overall. 

5. Modest and Inconsistent Effects: Quality of Life
Improvements in quality of life were small when compared to control groups and often did not last. However, studies tracking individuals over time showed moderate improvements, suggesting some benefit that may not always show up clearly in between-group comparisons. 

Overall, the findings suggest: 

  • CBT does improve real-world functioning, not just symptoms  
  • The strongest and most consistent benefits are in occupational (work) functioning  
  • Gains in social life, academics, and overall quality of life are more modest and variable  
  • Improvements in functioning do not always track directly with symptom reduction  

One notable nuance: CBT did not always outperform other active treatments (like medication or other therapies). This suggests that while CBT is effective, its benefits may partly overlap with broader therapeutic or support effects rather than relying on a single, unique mechanism. 

The Take-Away: 

CBT is a valuable, evidence-based treatment for adults with ADHD, especially for improving work functioning and overall daily life management. However, its impact on relationships, academic outcomes, and quality of life is more limited and less consistent, pointing to the need for more targeted or combined approaches in those areas. 

 

June 9, 2026

When ADHD and Epilepsy Overlap, Cognitive Impacts Add Up

The Background:

ADHD and epilepsy are the two most common neurological disorders in children and adolescents. Additionally, they appear as co-diagnoses more often than chance would predict. Roughly a quarter of children with epilepsy also have ADHD, and children with ADHD face a 2.5-times greater risk of developing epilepsy than their peers. 

Clinicians have long suspected that carrying both diagnoses compounds cognitive difficulties, but no rigorous quantitative review has mapped out exactly how much, or in what ways. This new meta-analysis now fills that gap. 

The Study:

The team pooled data from peer-reviewed studies that included children and adolescents diagnosed with both conditions alongside at least one comparison group: children with neither condition, children with epilepsy alone, or children with ADHD alone. To capture the breadth of thinking skills, they constructed a general intelligence factor drawing on six cognitive domains: 

  • Crystallized intelligence — accumulated knowledge and its application 
  • Fluid reasoning — tackling novel problems through logical thinking 
  • Working memory — holding and mentally manipulating information in the short term 
  • Processing speed — executing simple or well-practiced mental tasks quickly 
  • Reaction time — responding rapidly to basic stimuli 
  • Long-term memory and fluency — efficiently storing and later retrieving new information 

The Results:

Across eleven studies (995 participants), children and adolescents with both conditions scored moderately lower on general intelligence than those with epilepsy alone. The same pattern held across all six cognitive domains. Seven studies (785 participants) comparing the dual-diagnosis group with those who had ADHD alone found an equally consistent moderate deficit, replicated in every domain. 

The clearest signal emerged when researchers compared children and adolescents carrying both diagnoses to typically-developing peers. Seven studies covering 427 individuals revealed a substantially larger gap in general intelligence, with the effects of the two conditions appearing to be roughly additive, meaning the combined burden was approximately equal to the sum of each condition's individual impact. This pattern held across five of the six domains. 

The Interpretation:

The results come with meaningful caveats. Variability across individual studies was moderate in the first two comparisons and high in the third, reflecting real differences in how studies were designed, which populations they sampled, and how they measured cognition. While there was no sign of publication bias in the first group, it was not assessed in two of the three analyses. 

The authors describe “a widespread profile of cognitive dysfunction” in children and adolescents with both epilepsy and ADHD, while underscoring that the substantial variability between studies warrants caution in drawing overly precise conclusions. The findings nonetheless carry practical weight: children managing both conditions may need more intensive cognitive screening and support than current clinical practice routinely provides. 

June 3, 2026

Exercise May Ease Social Difficulties in Young People with ADHD, New Meta-Analysis Suggests

The focus on children and adolescents with ADHD often revolves around behavioral issues and academic difficulties, but the social struggles are real. Around 60% of youth with ADHD experience meaningful difficulties in social skills, reading social cues, and forming reciprocal relationships with peers. Over time, these struggles can raise the risk of anxiety and depression. 

Medication remains the primary treatment for ADHD, with stimulants like methylphenidate (Ritalin) being the most commonly prescribed. While effective at reducing core symptoms such as inattention and impulsivity, medication has not been shown to improve social behavior or peer relationships.

The Background: 

Exercise has recently emerged as a promising adjunctive therapy. A newly published meta-analysis examined whether structured physical activity can specifically improve social functioning in young people with ADHD. It builds on a previous review from 2015, addressing gaps that earlier work left open: social outcomes were rarely treated as a primary focus, and no prior analysis had systematically compared exercise types or asked how much exercise is actually needed to see benefits. 

The Study: 

The analysis included 13 randomized controlled trials involving 703 participants aged 6 to 18, all clinically diagnosed with ADHD. Only exercise programs lasting at least four weeks were considered. Studies that combined exercise with other therapies, such as psychotherapy, were excluded to isolate exercise's specific effects. 

The researchers used a technique called network meta-analysis, which allows different interventions to be compared against one another even when they haven't been tested head-to-head, alongside dose-response modeling to identify how much exercise produces the greatest benefit. 

  • Closed-skill exercise: takes place in stable, predictable environments where movements can be planned in advance  (such as in gymnastics, track and field, or strength training). 
  • Open-skill exercise: unfolds in dynamic settings that demand constant adaptation  (team sports such as basketball or soccer, and those requiring specific hand-eye coordination such as table tennis). 
  • Multicomponent exercise blends both: a session might begin with a structured, self-directed drill (closed-skill) before transitioning into reactive, opponent-driven play (open-skill). 
  • Mind-body exercise integrates movement, mental focus, and controlled breathing (includes practices like yoga, tai chi, and qigong). 

Results: 

The most striking results came from closed-skill exercise: across four studies involving 92 participants, it was associated with a very large reduction in social dysfunction. Open-skill exercise, by contrast, showed no measurable improvement across four studies with 91 participants. Multicomponent exercise (the group combining elements of both open- and closed-skill) reported large gains in two smaller studies with 33 participants.  

Mind-body exercise showed a moderate benefit across three studies involving 44 participants. 

The dose-response analysis offered a practically useful finding: 30 to 60 minutes of moderate-intensity exercise per day appeared to produce the best outcomes, with a minimum of roughly 15 to 30 minutes daily needed to achieve any meaningful benefit. 

The Take-Away: 

The results are encouraging but should be interpreted carefully. The number of studies in each category was small (two to three studies each), and sample sizes were modest, meaning the findings may not hold up as more evidence accumulates. The absence of publication bias is reassuring, as is the use of rigorous methodology, but this remains an early-stage evidence base. Larger, well-designed trials are needed before firm clinical recommendations can be made. 

For now, the findings position structured physical activity  (particularly closed-skill and multicomponent exercise) as a plausible complement to existing ADHD treatment, specifically targeting the social difficulties that medication tends not to address. The practical dose guidance is a useful starting point: around half an hour of moderate daily exercise as a minimum, with an hour as the apparent sweet spot. As low-risk additions to a treatment plan go, that’s a relatively accessible bar for most families to consider alongside professional guidance. 

May 24, 2026