Autism Background

1. What is autism?

Autism spectrum disorder (ASD) is a developmental disability that results from differences in how the brain functions. People with ASD may communicate, interact, behave, and learn in different ways. Signs of ASD begin during the early childhood years and usually last throughout a person’s life.

Autism spectrum disorder (ASD) is a developmental disability that can cause significant social, communication and behavioral challenges. There is often nothing about how people with ASD look that sets them apart from other people, but people with ASD may communicate, interact, behave, and learn in ways that are different from most other people. The learning, thinking, and problem-solving abilities of people with ASD can range from gifted to severely challenged. Some people with ASD need a lot of help in their daily lives; others need less.

2. Why do we need to know how many children have ASD? 

Findings from the MN-ADDM help us understand more about the number of children with ASD, the characteristics of those children and the age at which they are first evaluated and diagnosed.

MN-ADDM’s findings can be used to promote early identification of ASD, plan for ASD services/supports, identify training needs, guide future ASD research, and inform policies promoting improved outcomes in health care and education for individuals with ASD.

Report Findings

3. What are the prevalence estimates for ASD in MN?

Using data from 2018, MN-ADDM researchers found 1 in 36 (2.8%) 8-year-old children were identified with ASD in parts of Anoka, Hennepin, and Ramsey counties. This percentage is higher than the overall ADDM Network estimates of those identified with ASD (2.3% – or 1 in 44 children) in communities where ASD was tracked in 2016.

4. How do these MN prevalence estimates relate to the national average?

The estimated prevalence of autism in the MN-ADDM surveillance area is higher than the overall prevalence estimated for the 11 communities in the United States where CDC tracked ASD in 2018. This is the third time Minnesota has been a part of the ADDM network and we are working to expand our geographic area. The findings in this report reflect 10,081 8-year-old children concentrated in a large metropolitan area (i.e., portions of Anoka, Hennepin, and Ramsey counties). Higher prevalence rates in the Minnesota data as compared to the overall ADDM estimate may be due in part to a concentration of services and supports in the metropolitan area and the availability of both education and health source records for review.

5. When is ASD first being diagnosed?

In the reported area in Minnesota, in 2018, we identified ASD much later than when first concerns often develop. The median age of first ASD diagnosis in our report was 5 years and 3 months of age—the latest in the ADDM Network. This lag between noted developmental concerns and age of first diagnosis is concerning due to the importance of early intervention. 

Data from 4-year-old children in Minnesota suggests that more children are getting diagnosed earlier; Minnesota 4-year-olds were identified at 1.8 times the rate of 8-year-olds. This suggests that many children are diagnosed at young ages, but we continue to diagnose ASD in children in later childhood, as well.

In addition, only 45% of children identified with ASD received an evaluation prior to age 3. Based on the findings, Minnesota needs to continue to find ways to lower the age of first evaluation by community providers. With close to 3% of the population of 8-year-old children having ASD, it is important to continue efforts to support diagnostic, educational, and treatment options for children with ASD. Minnesota currently has a workforce and provider shortage in the area of ASD diagnosis and treatment, and continued efforts are needed to train, recruit and retain professionals and support workers in the field of ASD, particularly individuals from racially, culturally and linguistically diverse backgrounds.

Further, Minnesota has invested in early intervention to help children and families gain early access to early intervention services. Minnesota’s Early Intensive Developmental and Behavioral Intervention (EIDBI) Benefit provides early intensive intervention for people with ASD and related conditions. To learn more about the EIDBI benefit follow this link: https://mn.gov/dhs/partners-and-providers/news-initiatives-reports-workgroups/long-term-services-and-supports/eidbi/eidbi.jsp

6. Does this data show that Minnesota has the third highest rate of ASD in the United States?

The data shows that within the states and geographic areas included in the ADDM Network, MN-ADDM data shows the third highest rate for 8-year-olds (and the second highest rate for 4-year-olds). MN-ADDM data reflects ASD prevalence estimates in three counties in Minnesota. It does show that within these counties, there is a high rate of ASD among 8-year old children in 2018. MN-ADDM does not know the estimated ASD prevalence rate across the entire state of Minnesota. To estimate the rate for the entire state of Minnesota, researchers would need to expand the geographic region in which data is collected.

7. Does this data show that the prevalence rate of ASD in Minnesota is 1 in 36?

We do not know the estimated autism prevalence rate across the entire state of MN. In order to estimate this rate, we’d need to expand the geographic region in which we are able to gather data. This data tells us that the estimated prevalence rate of autism for 8-year-olds in parts of Anoka, Hennepin, and Ramsey counties is 1 in 36. The rate for 4-year-olds is 1 in 44.

8. Do these results tell us anything about the reasons for a higher prevalence of ASD in two Minnesota counties?

Tracking prevalence is important to help us understand more about children with ASD; however, this data does not tell us anything about the reasons ASD prevalence is higher in Minnesota. We anticipated a higher prevalence rate compared to the national estimate due to a concentration of services and supports in the metropolitan area where this prevalence data was obtained.

9. How do these findings about prevalence of ASD compare to previous studies about ASD in Minnesota?

This project builds on earlier ICI work that estimated the prevalence of ASD among Somali and non-Somali children in in Minneapolis. The first project, conducted in Minneapolis, was the largest project to date to look at the number and characteristics of Somali children with ASD in any U.S. community. The findings of that project, published in 2014, showed notable differences in the prevalence of co-occurring intellectual disability with ASD between children from different ethnic groups.

The MN-ADDM project looks more closely at some of those differences among children in the broader three-county area. It is important not to compare the findings from the previous Minneapolis Somali Autism Prevalence Project because the geographic area was different, the age of the children included in the project was different and it was in a different year.

This is the third time Minnesota has been included in the ADDM network. In 2018 and 2020, we presented findings from children who were 8 years old in 2014 and 2016 and residents of parts of Hennepin and Ramsey counties. In 2018, we found no significant statistical differences in ASD prevalence across race/ethnicity and no significant differences in the prevalence of intellectual disability with ASD across race/ethnicity. In 2020, we found that Hispanic children had a lower ASD prevalence than Black, non-Hispanic children, and Black, non-Hispanic and Hispanic children with ASD were more likely to have intellectual disability than White children with ASD.

There have been two other studies conducted in Minnesota that specifically look at ASD prevalence and the Somali community. It is important to know that these two previous studies used different methods and focused on different groups of children. Thus, making comparisons should be avoided. You can learn more about these two previous studies by clicking on the links provided here:

A Qualitative Study of Families of Children with Autism in the Somali Community: Comparing the Experiences of Immigrant Groups. Minnesota Department of Health Report to the Minnesota Legislature 2014.  PDF

Autism Spectrum Disorders Among Preschool Children Participating in Minneapolis Public Schools Early Childhood Special Education Programs PDF PDF .   This report provided information on the rates of preschool special education program participation in MPS only.

Data Collection Approach

10. What data was gathered to determine the results?

The information was gathered from health and education records of children who lived in parts of Anoka, Hennepin, or Ramsey counties and who were 8 years old or 4 years old in 2018.

11. Why is the data from 2018 and not more recent?

ADDM uses a rigorous and labor-intensive data collection process. It takes a lot of time to gain access to the data and to conduct the detailed review and analyses for the entire ADDM network. 

12. How and where was this information collected?

The ADDM Network estimates the number of children with ASD using a systematic record review method. Records that included various billing codes from the International Classification of Disease, Ninth Revision (ICD-9) or International Classification of Diseases, Tenth Revision (ICD-10) or special education eligibility codes were requested from health and education sources. Children ages 4 or 8 who had a parent or guardian who lived in one of the surveillance areas during 2018 were classified as having ASD if they had:

  1. a written ASD diagnosis by a qualified professional, 
  2. a special education classification of autism, OR
  3. an ASD ICD code obtained from administrative or billing information

13. Why was the data not collected statewide?

MN-ADDM was funded to estimate the prevalence of 4- and 8-year-olds with ASD and with intellectual disabilities (ID) in Anoka, Hennepin, and Ramsey counties. This project also identified differences in prevalence, characteristics and age of diagnosis across demographic groups, including two large racial/ethnic groups unique to the area – Somali and Hmong children.

Many other ADDM sites supplement their funds with state dollars. The MN-ADDM project is only funded by the CDC, and our geographic area is limited by availability of resources. Having access to a larger geographic area would increase the MN-ADDM population size included in the identification of prevalence. This would provide more information about the geographic variation among regions and likely identify sufficient numbers of children in diverse racial, ethnic and linguistic populations to draw conclusions about differences in prevalence estimates and disparities.

MN-ADDM is a valuable resource for the state of Minnesota, but it will need more funding to support expansion into more communities in the state that would enable us to provide statewide estimates.

14. In the future, how could the number of children included in MN-ADDM be increased?

The population is based on access to records in school districts and clinics within Anoka, Hennepin, and Ramsey counties. To increase the geographic scope, any additional counties would need to border these three counties to be analyzed per CDC methodology. Additional funding would also need to be secured to expand the geographic area of MN-ADDM. For the 2018 review of data, MN-ADDM partnered with six school districts and one charter school. 

15. Why study 4- and 8-year-olds instead of adults?

The CDC's ADDM Network methodology is standardized across all data years and has estimated the prevalence of autism for 8-year-olds since its first data cycle and continues to do so. By age 8, a child with autism should have been identified either clinically or through the education system. 2018 was the first year that all ADDM Network sites were funded to collect data on 4-year-old children.

16. Are the diagnostic criteria different for the presentation of ASD in girls?

Diagnostic criteria used to identify ASD are the same across sex, and racial and ethnic groups. In Minnesota, more males than females were identified with ASD. This is consistent with previous national estimates on ASD and sex.                   

17. How have quality and accuracy of results been ensured?

Established protocols have been followed in the planning, gathering, and analysis of all data. Specifically, the standard criteria used as part of the ADDM Network method ensures that all records are evaluated and reviewed in the same way and that all children are defined as having ASD using the same definition. The CDC monitors the project to ensure adherence to CDC methods.

18. What were the criteria used in the MN-ADDM data to confirm whether a child had ASD or not? DSM-IV or DSM-5?

Children were classified as having ASD if they had:

  1. a written ASD diagnosis by a qualified health professional, 
  2. a special education classification of autism, OR
  3. an ASD ICD code obtained from administrative or billing information

19. What role has the community had in the project?

MN-ADDM collaborates with a wide variety of community ASD organizations and several Minnesota state agencies including the Minnesota Departments of Education (MDE), Minnesota Department of Human Services (DHS), and Minnesota Department of Health (MDH). School districts and clinics are important community partners.

Racial and Ethnic Group Analysis

20. Why does MN-ADDM focus on the Somali and Hmong populations in its project?

 It is important for us to understand ASD prevalence across different communities in Minnesota. This project builds on earlier ICI work entitled the Minneapolis Somali ASD Prevalence Project that estimated the prevalence of ASD among Somali and non-Somali children in Minneapolis. That project is the largest project to date to look at the number and characteristics of Somali children with ASD in any community within the United States. The findings of that 2014 project, showed notable differences in ASD prevalence and co-occurring conditions, such as intellectual disability, between children from different ethnic groups in Minneapolis. Other studies conducted in the United States have identified disparities among children with autism from racially and ethnically diverse backgrounds in terms of age of diagnosis and access to and utilization of services.

The MN-ADDM project looks more closely at possible differences among children across a variety of racial and ethnic groups in the broader three-county area so that we can expand the number of children in sub-populations and better understand if there are estimated prevalence differences and disparities

21. How did the data collection approach estimation of prevalence of ASD for the different racial/ethnic groups?

MN-ADDM collected racial and ethnic data per CDC methodology, but it also looked at ASD and intellectual disability prevalence in two racial/ethnic groups with high populations in Minnesota: Somali and Hmong. To do this, data is gathered on language spoken in the home.

22. How does the Somali prevalence data compare to other racial and ethnic communities?

Data from 2018 is currently being analyzed. Please return to this website at a later date for updates. 

23. Does this data show that Somali children have the highest rates of ASD in Minnesota?

Data from 2018 is currently being analyzed. Please return to this website at a later date for updates.

Critical Issues and Next Steps

24. Is this an epidemic or crisis? Why are more children being identified with ASD?

A large number of children are identified as having ASD and the prevalence rates have certainly increased over time. We do not know whether more children are truly developing ASD than in the past or whether we are doing a better job at identifying it. Additionally, the ADDM methodology changed in 2018, and new sites were added, so prevalence across years may not be directly comparable. Tracking prevalence is important to help us understand more about children with ASD; however, this data does not tell us anything about the reasons why ASD prevalence is high within the United States and higher in Minnesota. The higher prevalence estimate compared to ADDM-wide estimates is not unanticipated in a large metropolitan area and given we have both education and clinic site records to review.

25. What is the cause of autism? What is being done to find a cause(s)?

MN-ADDM was designed to identify the prevalence of autism in 4- and 8-year-olds in Anoka, Hennepin, and Ramsey counties. Its purpose was not to figure out the causes of autism. It can help MN-ADDM understand who lives with autism so it can advocate for resources and policies that support families and individuals with ASD.

ASD is a complex condition, and most scientists who study ASD believe that there is no single cause. There is strong evidence that ASD is genetic and involves multiple genes. There may also be environmental and other factors that make a child more likely to have ASD. We do not yet know enough about environmental factors that might be linked to autism to make definitive statements. Understanding more about these factors will help us learn about the causes of ASD. It is important to remember that no single risk factor leads to ASD, and most of these risk factors are outside of an individual’s control.

There are many researchers interested in understanding the causes of autism, including some at the University of Minnesota who are looking at the genetics of autism and at early brain development in children at risk for autism. MN-ADDM is happy to connect you with specific research studies if you are interested.

26. What is the CDC doing to study the causes of ASD?

For more information on CDC ASD research, please visit https://www.cdc.gov/ncbddd/autism/research.html

27. Do immunizations cause ASD?

Research has not found evidence that vaccines cause ASD. The original study that suggested a link was later found to be untrue and the article retracted because the researcher misrepresented his findings and used unethical methods. MDH provides more information about this topic, but we also recommend you talk with your child's pediatrician about your concerns. Visit https://www.health.state.mn.us/immunize .

28. Immunizations rates for Somali children have gone down over time, so why did ASD rates go up?

This tells us that avoiding vaccines does not prevent ASD in children. We understand that parents are fearful their child may develop ASD and want answers for what causes ASD. We know it's not vaccines, but we don't yet know what all of the causes of ASD are and finding those answers would help put to rest fears about vaccines. We hope that resources can be dedicated to understanding what really does cause ASD and, even more importantly, what treatments, supports, and services work to improve the lives of people with ASD and their families. It is important to talk with your doctor at your well child visits about your child's development and also about any concerns you might have about vaccinations.

29. Why are we still looking at prevalence when we know a high percentage of children in Minnesota have ASD?

Documenting prevalence is a necessary step towards establishing the need for developing more services and supports to meet the demand in Minnesota and also for identifying the need for more research. While many children have been diagnosed with ASD, MN-ADDM data helps to better understand differences in prevalence related to geographic location, race, ethnicity, and linguistic background. Continuing to expand our knowledge about prevalence to a larger geographic area helps us move closer to being able to answer these types of questions with confidence and to better plan for services and supports for individuals with ASD and their families.

30. What are possible next research steps?

ADDM data has played an important role in documenting the number of children identified with ASD in the United States. This data has laid the groundwork for ongoing ASD research such as who is likely to be identified with ASD, when children are identified with ASD, and how to best support children with ASD and their families. MN-ADDM will allow for the same work to happen in the state of Minnesota, including the ability to study the differences between racial and ethnic communities in Minnesota.

More About MN-ADDM and ASD Resources

31. What other community work and resources does MN-ADDM provide?

MN-ADDM actively engages culturally and linguistically appropriate dissemination, educational and outreach activities designed to target hard-to-reach communities. MN-ADDM partnered with the CDC-funded "Learn the Signs. Act Early" (LTSAE) project and Help Me Grow MN to conduct outreach and educational activities on early developmental screening and early identification in under-identified communities such as Latino, Hmong, and Somali communities. MN-ADDM together with MN Act Early has translated and customized ASD and LTSAE outreach materials and resources for our local diverse communities.

A short film series was developed in partnership with the MN Department of Human Services to raise awareness of ASD for local diverse communities (e.g. Somali, Hispanic, Hmong, African American, and American Indian). They are designed to help families access evaluation resources, early intervention services, and ASD support resources. https://mn.gov/autism .

32. What are state agencies in MN doing to address the issue of high prevalence rates of autism in our children?

Representatives from the Minnesota Departments of Education, Health, Human Services, and Employment and Economic Development, in partnership with other stakeholders including providers, parents and caregivers, clinicians, researchers, self-advocates, and advocates continue to work towards coordination across the range of services available.

People with ASD or related conditions often need a variety of supports and services over the course of their lifetime. To meet each individual person and family’s needs, the state of Minnesota offers many programs, including those for health care, education, home and community-based supports, and mental health services.

Even before a child receives a formal diagnosis, local school districts serve as a resource for referrals and services. For children birth to age 5, families can contact Minnesota Help Me Grow. For children over the age of 5, contact local school districts can be contacted for special education services.

County public health, social services, or tribal offices can provide local information and referrals, including advocacy, child care, community resources, county services, education, and medical specialists. For information and referrals, contact the child’s local county agency or tribe.

If you have concerns or have recently received a referral from a child’s school or child care provider, and a diagnosis of ASD or a related condition is suspected, contact your doctor or locate a provider to complete an assessment at Minnesotahelp.info or contact the Disability Hub at 1-866-333-2466 or https://mn.gov/autism .

33. When the rate of ASD is growing and so many more children are being diagnosed, how will we be able to provide services to all children with ASD? How much more will it cost to serve children, youth and adults given this new prevalence estimate?

The rates of ASD are high and it is critical for children to get assessed and diagnosed early so that they can get early intensive intervention services. These services and supports do cost money and most people with ASD will require some time of support throughout their lives. As a community, we will need to come together to ensure our elected officials understand the importance of access to affordable services and supports. A critical component of the service system is having enough qualified and trained professional staff with the skills to deliver the interventions. This too will need to be addressed.

34. Many treatments and supports for children with ASD are expensive, how can families afford them?

In Minnesota, both private and public health insurers are required to offer services. 

  • MDH works to make sure children and families can live their healthiest lives from prenatal care and healthy beginnings, through a youth’s transition to adulthood.
  • Continuing to know the prevalence of ASD in Minnesota over time helps MDH prepare our systems and workforce to best meet the needs of individuals with ASD and their communities.
  • MDH also strives to improve health equity across the state. Having more data about autism helps MDH identify and address health disparities by race, location, gender, disability status, and other differences.