Understanding the link between Autism Spectrum Disorder and Immigration in Manitoba

Autism Spectrum Disorder (ASD) diagnoses have been increasing. According to the U.S. Centers for Disease Control and Prevention (CDC), 1 in 36 eight-year-old children in the United States is now diagnosed with ASD—double the rate from just ten years ago. Although the causes for such increase are still not fully understood, research into potential risk factors is essential for improving early diagnosis, intervention, and possibly even prevention.

In Manitoba, the Rehabilitation Centre for Children (RCC) is the primary publicly funded referral site for diagnosing ASD in children six years old and younger. Clinicians have noted a trend: a disproportionately high number of referrals appear to come from immigrant families seeking ASD evaluations for their children.

This observation aligns with international findings. Studies from countries such as the United Kingdom, Australia, Sweden, Norway, the U.S., and France have reported higher rates of ASD among children from immigrant backgrounds. Notably, the CDC’s most recent data shows a historic shift in the U.S.—for the first time, ASD rates are now higher among children from racial and ethnic minority groups than among white children.

Despite this growing body of international research, Canada has lagged. Until recently, there was a significant gap in Canadian data exploring the association between immigration and ASD. Given Canada's high rate of immigration, this is a critical area for further study.

With the support of ENRRICH and CHRIM, we conducted two studies examining the potential relationship between immigration and instances of ASD. Our first study examined patient data from RCC between 2016 and 2021 and compared the rate of ASD diagnoses between children with one or more ‘immigrant’ parents and children born to Manitoba residents. We found that 36% of children diagnosed in this time period had at least one immigrant parent. This is statistically significantly higher than the proportion of immigrantss in Manitoba (19% in 2016 and 21.7% in 2021). Furthermore, children of immigrants diagnosed with ASD displayed lower rates of family history for ASD (16.3% vs 33.3%). These children also had lower rates of associated neurological comorbidities (4.2% vs 6.4%). This highlights the potential of environmental factors that may increase the risk of ASD in children of immigrant families. This study was recently published – read more about it here: https://doi.org/10.1093/pch/pxae031 

While our 2021 study was the first of its kind in Canada to study the relationship between ASD and immigration, it was limited with the extent of immigration details. Therefore, the second study utilized population-level data to further understand immigration as it related to cases of ASD. For our second study, we linked RCC’s ASD dataset with the Manitoba Population Data Repository to be able to examine the health, education, and sociodemographic information for all Manitoba residents between 2016 to 2022. In this study, we found that, of all the children diagnosed with ASD in Manitoba during this period, 47.2% were born to immigrant families: 41.8% of the children were born in Canada, and 5.4% were born outside of Canada. Even though immigrant families made up 29% of the total study sample, children born to immigrant families made up almost half of the total ASD diagnoses. When comparing risk, children of immigrant parents born in Canada were at higher risk of developing ASD than children of immigrant parents born outside of Canada and than Canadian children born to Canadian parents. 

When looking closer at specific immigration data, such as emigrated region, mothers’ arrival date in Canada, refugee status, and comparisons between immigrant mothers versus fathers, we found that the children of all immigrants who were born in Canada, besides children of European immigrants, were more at risk of developing ASD. As well, we found that the length of time that immigrant mothers had been in Canada did not impact the risk of ASD, meaning that children of mothers who have stayed in Canada for over 10 years had the same risk of developing ASD as children of mothers who arrived in Canada within 10 years. Of note, the refugee status of immigrant families did not further increase the risk of their children developing ASD as compared to those who immigrated under less severe circumstances. Finally, when considering which parent immigrated to Canada, children born to families where both parents were immigrants were most at risk of developing ASD and children with immigrant mothers posed the second highest at risk.

To better understand the findings from our two studies, we looked at research from around the world that has examined the role of immigration in the development of ASD. A range of environmental and epigenetic factors have been proposed to explain this association. These include differences in diet, parental mental health before and after conception, stress related to adapting to a new culture (also known as acculturation stress), and the loss of social support networks that often occurs when families move away from their communities.

While these factors offer valuable insight, our research—like many other studies to date—has primarily shown an increased risk of ASD among immigrant populations without identifying a single, clear cause. The reasons behind this association remain unclear, but one promising area for further exploration is the experience of integration: how immigrant families are welcomed and supported in their new environments. 

This is why our work in this area continues. We are currently conducting focus groups with both healthcare providers and immigrant families to help identify the most pressing questions and gaps in knowledge. These conversations are key to guiding future research on how immigration may influence ASD, and ultimately, how to support families more effectively.

Published August 1, 2025

ABOUT THE AUTHOR

Florencia Ricci MD, PhD (she/her)

Dr. Florencia Ricci currently works as a Developmental Pediatrician, and as an Assistant Professor at the University of Manitoba. Her research is focused on the development of new knowledge and understanding of the impact of congenital heart disease and its complex care on the neurodevelopment of children. Dr. Ricci also dedicates part of her research to investigate the neurodevelopmental outcomes of children born prematurely