September 26, 2024

Norwegian Population Study of Adolescents Finds Interpersonal Trauma Much More Likely Than Situational Trauma to Lead to ADHD Diagnosis

Potentially traumatic experiences (PTEs) refer to events where someone is exposed to situations that involve threats to life, serious injury, or danger to themselves or others. These events can include things like accidents, violence, or the death of someone close. PTEs are significant because they can have lasting effects on a person's mental health.

A research team from Norway, working with a collaborator from the U.S., used their country’s universal health care system to study how PTEs affect the mental health of children and adolescents in Hordaland County, which includes the city of Bergen. They wanted to see how experiencing PTEs influenced the likelihood of these young people seeking help from child and adolescent mental health services (CAMHS) or being diagnosed with psychiatric disorders, including ADHD.

In 2012, the study invited all 19,439 teenagers born between 1993 and 1995 in Hordaland County to participate. These teens were 16 to 19 years old at the time. Out of this group, 9,555 teens agreed to let the researchers link their personal data with the National Patient Registry (NPR), which keeps track of health records. There was no significant difference in the types or number of PTEs between those who agreed to this data sharing and those who did not.

After removing participants with incomplete information, the researchers were left with 8,755 teens. These teens’ psychiatric diagnoses, including ADHD, were taken from the NPR. The researchers asked the participants if they had ever experienced specific traumatic events, such as:

  • A serious accident or disaster
  • Violence from an adult
  • Witnessing violence against someone they cared about
  • Unwanted sexual actions
  • The death of someone close to them

If a participant reported experiencing the death of someone close, they were asked to specify who it was (a parent, sibling, grandparent, other family member, close friend, or romantic partner). One limitation of the study was that it did not ask about bullying, which could also be a traumatic experience.

Key Findings

The researchers divided the teens into three trauma groups based on their experiences:

  1. Low Trauma Group (88% of participants): These teens had not experienced anything more traumatic than the death of a grandparent.
  2. Interpersonal Trauma Group (6% of participants): These teens had experienced or witnessed violence, and some had also been exposed to sexual abuse, accidents, or the death of family members.
  3. Situational Trauma Group (6% of participants): These teens had experienced accidents and multiple deaths (including of close friends), but had less exposure to violence.

Other Important Factors

Teens in the situational and interpersonal trauma groups were more likely to see their economic situation as worse than those in the low trauma group. For example, 11% of the situational trauma group and 17% of the interpersonal trauma group considered themselves economically worse off, compared to just 6.1% of the low trauma group. Also, fewer parents of teens in the two higher trauma groups had higher levels of education, which can impact family support and resources.

ADHD and Trauma

After adjusting for gender and parental education, the researchers found that:

  • Teens in the situational trauma group were more than twice as likely to be diagnosed with ADHD compared to those in the low trauma group.
  • Teens in the interpersonal trauma group (who had experienced or witnessed more violence) were more than twice as likely to be diagnosed with ADHD compared to those in the situational trauma group.

The effect was even stronger when comparing the interpersonal trauma group to the low trauma group. Teens in the interpersonal trauma group were almost five times more likely to be diagnosed with ADHD than those in the low trauma group.

Study Limitations

One limitation of the study is that while the researchers acknowledged that sex and socioeconomic status (SES) are important factors in the relationship between trauma and psychiatric disorders, they did not directly adjust for SES. However, they did indirectly account for it by considering the education levels of the parents, which is closely related to SES.

Conclusion

The study showed that adolescents who experience more interpersonal trauma (like violence or sexual abuse) are at a significantly higher risk of being diagnosed with ADHD. The findings suggest that it’s important to pay special attention to teens who experience both situational and interpersonal traumas, especially those exposed to interpersonal violence. Early intervention and support could be key to helping these adolescents manage their mental health.

Annika Skandsen, Sondre Aasen Nilsen, Mari Hysing, Martin H. Teicher, Liv Sand, and Tormod Bøe, “Associations Between Distinct Trauma Classes and Mental Health Care Utilization in Norwegian Adolescents: A National Registry Study,” Child Psychiatry & Human Development (2024), https://doi.org/10.1007/s10578-024-01671-9.

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US Study Highlights the Social Roots of ADHD

While ADHD is a developmental disorder, shaped by biology and genetics, growing evidence shows that it is also influenced by the social and environmental conditions in which children grow up. Research on the social determinants of health emphasizes that development is shaped not only by biology but also by factors such as family income, access to healthcare, neighborhood safety, and material stability. These factors can affect both how developmental challenges appear and whether they are recognized and diagnosed. 

Children facing socioeconomic disadvantage consistently show higher risks of developmental and behavioral difficulties. Chronic stress linked to poverty – including financial strain, food insecurity, and limited access to resources – has been associated with problems in attention, emotional regulation, and daily functioning. Children from lower-income families also tend to experience more severe ADHD symptoms and face greater barriers to ongoing care. 

Neighborhood conditions matter as well. Unsafe environments can limit opportunities for play and social interaction while increasing caregiver stress, all of which may influence children’s behavior and development. Material hardships, such as food insecurity, can further undermine stability at home. 

The Study:

The study analyzed six years of data from the National Survey of Children’s Health (2018–2023), covering more than 205,000 U.S. children aged 3 to 17. After accounting for age, sex, race and ethnicity, region, family structure, survey year, and other social factors, the researchers found a strong income gradient in ADHD prevalence. Compared with children in households earning at least four times the federal poverty level, those in households earning two to four times that level had 28 percent higher odds of ADHD. Odds rose to 70 percent higher in households earning one to two times the poverty level, and more than doubled among children living below the poverty line. 

Parental education showed a similar pattern. Compared with children whose parents had completed college, ADHD odds were 20 percent higher among those whose parents had some college education, 40 percent higher among those whose parents had only a high school education, and 80 percent higher among those whose parents had not finished high school. 

Children living in unsafe neighborhoods had nearly twice the odds of ADHD compared with those in safe neighborhoods, and food insecurity was also linked to almost double the odds. 

By contrast, race and ethnicity alone were associated with much smaller differences. Compared with non-Hispanic White children, children in non-Hispanic Black households had an 18 percent higher likelihood of ADHD, while children in Hispanic households had a 25 percent lower likelihood. No substantial differences were observed for children from other or multiracial households. 

Conclusion and Takeaway:

The study team concluded, “Children living in lower-income households, experiencing food insecurity, and residing in unsafe neighborhoods consistently showed higher prevalence and higher adjusted odds of both conditions. … Overall, these findings reinforce the need to view neurodevelopmental disorders within a broader social and structural framework.” 

It should be noted that this study is not aiming to name social factors as direct causes of ADHD. Rather, it points to socioeconomic disparities as contributing to the way ADHD develops and how it is treated. This type of research, as well as acknowledging barriers to care, is crucial for clinicians, counselors, teachers, etc., to consider when working with youth with ADHD. 

 

 

Norwegian Nationwide Population Study: Single Umbilical Artery Shows Weak Link to ADHD

Counting umbilical cord vessels is standard in prenatal ultrasounds and confirmed at birth. Single umbilical artery (SUA) occurs in about 1 in 200 cases, with roughly 10% associated with anomalies, including central nervous system defects. Isolated SUA (iSUA) means one artery is missing without other structural issues. 

Research on SUA, especially isolated iSUA, and childhood neurodevelopmental disorders (NDD) is limited and inconclusive. iSUA is linked to preterm birth and small-for-gestational age (SGA), both of which are NDD risk factors.  

This Norwegian nationwide population study aimed to assess NDD risk in children with iSUA at birth, the influence of sex, and how preterm birth and SGA mediate this relationship. 

The nation’s universal single-payer health insurance and comprehensive population registries made it possible to analyze all 858,397 single births occurring from 1999 to 2013, with follow-up continuing through 2019. Among these cases, 3,532 involved iSUA. 

After adjusting for confounders such as parental age, education, and maternal health factors, no overall link was found between iSUA and later ADHD diagnosis. However, females with iSUA had about a 40% higher risk of subsequent ADHD compared to those without iSUA, even after adjustment. 

The authors concluded, “The present study indicates that iSUA is weakly associated with ID [intellectual disability] and ADHD, and these associations are influenced by sex. This association is mediated negligibly through preterm birth and SGA. The associations were not clinically significant, and the absence of associations of iSUA with other NDD is reassuring. This finding can be useful in the counseling of expectant parents of fetuses diagnosed with iSUA.” 

 

Large Cohort Study Reports Association Between Eye Disorders and ADHD

Refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (distorted vision due to irregular curvature of the eye or lens), are common worldwide. These conditions affect 12%, 5%, and 15% of children, and rise significantly in adults to 26.5%, 31%, and 40%. Additionally, strabismus (misalignment of the eyes) and amblyopia (reduced vision in one eye from uneven image formation, often linked to strabismus) occur globally at rates of 2% and 1.4%, respectively. 

Visual impairment can affect children’s concentration in school, and studies suggest a link between eye disorders and ADHD. 

To investigate this relationship, two researchers – one based in the US and the other in Israel –carried out a nationwide retrospective cohort study using electronic medical records of all insured individuals aged 5 to 30 who were part of Maccabi Health Services, Israel’s second largest health maintenance organization, between 2010 and 2022. 

Of over 1.6 million insured members (2010–2020), inclusion/exclusion criteria and propensity score matching for age and sex were applied, along with a one-year wash-out period between the first eye diagnosis and ADHD diagnosis. In total, 221,707 cases were matched with controls without eye disorders at a 1:2 ratio, resulting in a cohort of 665,121 participants.  

Overall, those with any previous eye diagnosis were 40% more likely to have a subsequent ADHD diagnosis. This was slightly higher for females (45%) than for males (35%). It was also slightly higher for children and adolescents (42%) than for adults (37%).  

More specifically: 

  • Myopia (425,000+ participants): 30% higher ADHD rate. 
  • Hyperopia (120,000+) and astigmatism (175,000+): over 50% higher ADHD rate. 
  • Strabismus (13,000+): over 60% higher ADHD rate. 
  • Amblyopia (14,000+): 40% higher ADHD rate. 

The authors concluded that eye disorders are associated with ADHD. They noted these associations were more marked in females and children and adolescents, although, as noted above, those differences were small. They recommended that primary care providers and neurologists consider risk stratification for early screening, and that ophthalmologists refer high-risk patients for ADHD evaluation. 

 

 

February 10, 2026