Concussion Does Not Reduce Children’s IQs, Study Finds


Undoubtedly, one of the common experiences of parenthood is the anxiety parents experience when their kids get hurt. When concussions are involved in those injuries, that concern is amplified significantly. However, a recent study from the University of Calgary may allay some parents’ fears.

The findings, based on emergency room visits in children’s hospitals in Canada and the United States, show that pediatric concussions have no clinically meaningful effect on IQ or intelligence.

“Obviously there’s been a lot of concern about the effects of concussion on children, and one of the biggest questions has been whether or not it affects a child’s overall intellectual functioning,”

said senior author Dr. Keith Yeates, PhD, a professor in UCalgary’s Department of Psychology. Yeates is a renowned expert on the outcomes of childhood brain disorders, including concussion and traumatic brain injuries.

Hard to Get Data

The data on the outcomes has been mixed, and opinions in the medical community have varied.

“It’s hard to collect big enough samples to confirm a negative finding. The absence of a difference in IQ after concussion is harder to prove than the presence of a difference,”

Yeates said.

In the study, 300 children with orthopedic injuries are compared to 566 children with concussion diagnoses. The kids, who were drawn from two cohort studies, are eight to sixteen years old. The Canadian cohort includes information gathered from five ERs for children’s hospitals: Vancouver, Edmonton, Ottawa, Montreal (CHU Sainte-Justine), and Alberta Children’s Hospital in Calgary. Three months after their injuries, patients in the Canadian hospitals took IQ tests.

The U.S. cohort was conducted at two children’s hospitals in Ohio, wherein patients completed IQ tests three to 18 days, postinjury.

No IQ Difference

The study’s large sample size was made possible by combining the Canadian and American cohorts. Yeates and his co-authors, who are affiliated with universities in Calgary’s Mount Royal University, Edmonton, Montreal, Vancouver, Ottawa, Atlanta, Utah, and Ohio, were also able to test patients with a variety of clinical characteristics and demographics.

We looked at socioeconomic status, patient sex, severity of injuries, concussion history, and whether there was a loss of consciousness at the time of injury,” said Yeates. “None of these factors made a difference. Across the board, concussion was not associated with lower IQ.”

The children with concussions were compared to children with orthopedic injuries other than concussion to control for other factors that that might affect IQ, such as demographic background and the experience of trauma and pain. This allowed the researchers to determine whether the children’s IQs were different than what would be expected minus the concussion.

Reassuring Results

Lead author of the report and Georgia State University professor Dr. Ashley Ware, PhD, stated that parents should be informed about the study’s findings.

“Understandably, there’s been a lot of fear among parents when dealing with their children’s concussions. These new findings provide really good news, and we need to get the message to parents,”

Ware said.

“It’s something doctors can tell children who have sustained a concussion, and their parents, to help reduce their fears and concerns. It is certainly reassuring to know that concussions do not lead to alterations in IQ or intelligence,”

Dr. Stephen Freedman, PhD, co-author of the paper, added.

Another strength of the study is that it includes two cohort studies, one testing patients immediately after their concussions and the other three months later. That makes the claims even stronger.

“We can demonstrate that even in those first days and weeks after concussion, when children do show symptoms such as a pain and slow processing speed, there’s no hit to their IQs. Then it’s the same story three months out, when most children have recovered from their concussion symptoms. Thanks to this study we can say that, consistently, we would not expect IQ to be diminished from when children are symptomatic to when they’ve recovered,”

Ware said.


This study investigated IQ scores in pediatric concussion (ie, mild traumatic brain injury) versus orthopedic injury.

Children (N = 866; aged 8–16.99 years) were recruited for 2 prospective cohort studies from emergency departments at children’s hospitals (2 sites in the United States and 5 in Canada) 48 hours after sustaining a concussion or orthopedic injury. They completed IQ and performance validity testing postacutely (3–18 days postinjury; United States) or 3 months postinjury (Canada). Group differences in IQ scores were examined using 3 complementary statistical approaches (linear modeling, Bayesian, and multigroup factor analysis) in children performing above cutoffs on validity testing.

Linear models showed small group differences in full-scale IQ (d [95% confidence interval] = 0.13 [0.00–0.26]) and matrix reasoning (0.16 [0.03–0.30]), but not in vocabulary scores. IQ scores were not related to previous concussion, acute clinical features, injury mechanism, a validated clinical risk score, pre- or postinjury symptom ratings, litigation, or symptomatic status at 1 month postinjury. Bayesian models provided moderate to very strong evidence against group differences in IQ scores (Bayes factor 0.02–0.23). Multigroup factor analysis further demonstrated strict measurement invariance, indicating group equivalence in factor structure of the IQ test and latent variable means.

Across multisite, prospective study cohorts, 3 complementary statistical models provided no evidence of clinically meaningful differences in IQ scores after pediatric concussion. Instead, overall results provided strong evidence against reduced intelligence in the first few weeks to months after pediatric concussion.

  1. Ashley L. Ware, Matthew J. W. McLarnon, Andrew P. Lapointe, Brian L. Brooks, Ann Bacevice, Barbara A. Bangert, Miriam H. Beauchamp, Erin D. Bigler, Bruce Bjornson, Daniel M. Cohen, William Craig, Quynh Doan, Stephen B. Freedman, Bradley G. Goodyear, Jocelyn Gravel, H. Leslie K. Mihalov, Nori Mercuri Minich, H. Gerry Taylor, Roger Zemek, Keith Owen Yeates. IQ After Pediatric Concussion. Pediatrics, 2023; DOI: 10.1542/peds.2022-060515

Last Updated on October 7, 2023