History of concussion identified as the most important risk factor for maternal mental illness

According to a new study from ICES and the University of Toronto, people with a history of concussion have a 25% higher risk of serious mental health problems after childbirth.

The study highlights the importance of identifying individuals with concussion early in their prenatal care and highlights the need for long-term, trauma-informed support to protect their mental health.

We found that individuals with a history of concussion were significantly more likely to experience serious mental health problems, such as psychiatric emergency department visits or self-harm, in the years following childbirth.”

Samantha Krueger, lead author, registered midwife and PhD candidate in Health Research Methodology at McMaster University

The study was completed as part of Krueger’s MSc at the University of Toronto’s Institute of Health Policy, Management and Evaluation.

“This association was especially strong for people with no prior mental health history, meaning that concussion may be an important but overlooked risk factor during pregnancy and postpartum care,” Krueger adds.

The study followed more than 750,000 birthing people across Ontario between 2007 and 2017, tracking mental health outcomes for up to 14 years postpartum. Researchers found that among those with a history of concussion, 11% experienced serious maternal mental illness, compared to 7% of those with no previous concussion. Even after adjusting for several factors such as age, income and history of interpersonal violence, concussion was associated with a 25% increased risk of serious mental illness.

The study’s findings were especially striking among participants without pre-existing mental health diagnosis. In these individuals, a previous concussion increased the risk of developing a serious maternal mental illness by 33%, compared with those with no history of concussion.

Senior author Dr. Hilary Brown notes that the physical and emotional demands of parenthood can worsen the problems associated with concussion. “Sleep is critical for recovery from head injury, but sleep deprivation is a reality for many new parents,” said Brown, adjunct scientist at ICES and associate professor in the Department of Health and Community at the University of Toronto Scarborough.

“Cognitive impairment, sensitivities to light and sound, and the stress of caring for a newborn can all worsen the symptoms of a concussion, which in turn can increase the risk of mental health problems over time,” says Brown.

Given the biological links between brain injury and mental illness, the researchers advocate routine prenatal screening for concussions, provision of mental health resources, and the use of trauma-informed care during the postpartum period. “Our research highlights a critical need for healthcare providers to consider concussion history when supporting new parents,” Krueger added. “Early identification and long-term support can make a real difference in preventing serious psychiatric consequences.”

The study adds to growing evidence that reproductive care must include neurological and mental health factors to address the full spectrum of risks faced by birthing people. The researchers hope their findings will encourage healthcare providers and policymakers to prioritize concussion prevention in people of reproductive age and ensure adequate mental health care for new parents with concussions.