Why PATHS?

Compared to non-autistic young people, autistic youth are more likely to have co-occurring mental and physical health conditions. When these conditions are not managed well, especially during the transition from pediatric to adult health care, they may worsen over time. In addition, we still need to better understand exactly how socioeconomic status (SES), race, ethnicity, and sex affect the health of young autistic individuals. 

What will PATHS do?

Researchers will examine Medicaid health data on 1 million autistic youth and their non-autistic peers, ages 10-24 years, over a 5-year span with the goal of uncovering health and health services patterns that make a difference on long-term well-being. At each step, researchers will work to better understand how socioeconomic status, race, ethnicity, and sex make a difference in these patterns. The goal is to understand how patterns of health and health services use over time contribute to autistic young persons’ health as they get older. This new knowledge should improve our understanding of how, when, and whom we should be supporting to help autistic young people achieve better well-being.

What are PATHS' specific goals?

• To uncover different health patterns across age: Using statistical methods, researchers will identify groups of autistic and non-autistic young persons of different ages with different health patterns. Members of each group share a common pattern of mental/behavioral/neurodevelopmental (MBND; e.g., depression, sleep problems, ADHD), chronic physical (e.g., asthma, gastrointestinal problems), and acute physical (e.g., infections, injuries) health over a 5-year period. For example, one group might share frequent brain MBND health events (such as treatment for depression or ADHD) but have few chronic or acute physical health events. Another group might receive treatment for many chronic physical health conditions, such as asthma or diabetes, with relatively fewer MBND events and few acute physical health concerns.
• To uncover different health services patterns across age: Using similar methods, researchers will identify groups of autistic and non-autistic young persons of different ages with different health services patterns. Members of each group share a common pattern of services over a 5-year period. For example, one group might share a history of frequent visits to the emergency department or frequent inpatient stays but have fewer regular outpatient visits. Another group may share high medication use, with few inpatient stays or emergency visits and few outpatient visits.
• To learn how past health and services use patterns impact future health and well-being: Researchers will study how the measures of health and well-being in later years are different between autistic and non-autistic youth who had different health and health services patterns in the previous 5 years. Measures of long-term health and well-being include how long a person has had a specific disabling health condition; how frequently persons need to use inpatient or emergency care; and how often deaths occur. 

At every stage, differences will be measured and compared across persons based on their sex, socioeconomic status, and racial and ethnic identity to discover when, how, and for whom these factors make a difference in health, services use, and well-being.

How will researchers engage and collaborate with the community?

PATHS is supported by a Community Advisory Board composed of partners who share a commitment to supporting autistic youth with co-occurring health conditions. Community partners, including autistic young persons, parents, adult siblings, and healthcare providers meet quarterly to share ideas with the research team and carry out their own community activities and projects, in partnership with PHASES researchers. 

Preliminary research findings:

Smith, P. H., Ventimiglia, J., Wright, J., Rast, J. E., Schendel, D. E., Mullachery, P. H., Lee, B. K., & Shea, L. L. (2026). Brief Report: Healthcare Utilization and Expenditure Trends Among Autistic Transition Age Youth. Journal of Autism and Developmental Disorders. https://doi.org/10.1007/s10803-026-07271-x

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Carey ME, Holmes LG, Shea LL, Mandell DS, Schendel D, Lee BK, Lyall K. Trajectories of evidence-based treatment use in 8-to-29-year-old Autistic Medicaid Enrollees with Depression. 2026 AcademyHealth Annual Research Meeting. Oral presentation.  

Carey ME, Holmes LG, Shea LL, Mandell DS, Schendel D, Lee BK, Lyall K. Therapy and antidepressant use in autistic medicaid enrollees (8-29 years) with depression. 2026 Autism. 

Summary: Promoting access to effective depression treatment represents a crucial opportunity to mitigate increased autism suicide risk. We examined treatment trajectories for 8- to 29-year-old autistic enrollees of Medicaid who had been diagnosed with major depressive disorder. We identified four treatment trajectories: no/limited treatment (39%), gradual treatment decline (21%), late treatment initiation (14%), and continuous treatment (25%). The likelihood of having continuous treatment (versus no or limited treatment) was lower for Black enrollees, Hispanic enrollees, and those with co-occurring intellectual disability and highest for 8- to 12-year-olds and females. Improving treatment in autistic enrollees requires varied and multi-faceted approaches that must consider demographic and clinical factors.

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Yu J, Ventimiglia J, Smith P, Rast J, Rando J, Shea L, Frisbie S, Lee BK, Lyall K, Mullachery P, Rod NH, Schendel D. Longitudinal patterns of mental and physical health conditions in autistic adolescents and young adults and their non-autistic peers in Medicaid. Poster presentation at the 2026 International Society for Autism Research, Prague, Czech Republic.

Summary: 

We examined health patterns over time for mental, behavioral, and neurodevelopmental conditions (MBND); chronic physical conditions (CHPH); acute injuries and infections (ACPH) in autistic and non-autistic youth in different age groups between 10-28 years. We identified four different health profiles in each age and study group. At all ages and in all study groups, there was one subgroup that had virtually no co-occurring conditions, although the proportion of autistic youth in that subgroup tended to be lower than in the non-autistic youth. One subgroup with co-occurring MBND conditions was observed at all ages in autism, although was less commonly observed in the non-autistic youth. Another subgroup had high numbers of multiple co-occurring conditions across all types of conditions. Results highlight that there are different longitudinal health profiles in autistic youth of the same age – with subgroups with both very low or very high levels of co-occurring conditions – and stability in the health profiles in autism from mid-adolescence into young adulthood. These multiple health patterns in autistic adolescents and young adults may be linked to variation in concurrent services use, long term outcomes and underlying health determinants. 

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J.Yu, J. Ventimiglia, S. Paul, P. Smith, B. Lee, J. Rast, J. Rando, K. Lyall, L. Shea, N. Rod, P. Mullachery, D. Schendel. International Society for Autism Research 2025.

Prevalence of Mental, Behavioral, and Neurodevelopmental Disorders Among Autistic Tweens and Their Peers Enrolled in Medicaid.

Summary: We examined changes over time in the prevalence of health conditions that occur in autistic children and their non-autistic peers between the ages of 10 to 16. We observed that all children shared a common pattern of age changes in prevalence (e.g., small increases in mental health, pain and physical health conditions and decreases in common infections). But, there were big differences in prevalence of specific conditions between groups: for example, autistic children had much higher prevalences of mental, behavioral and neurodevelopmental conditions than children with intellectual disability and no autism, or children with no autism or intellectual disability. We also saw large differences in health burden by study group with the number of co-occurring of mental, behavioral and neurodevelopmental conditions consistently highest in autistic young adolescents. Results highlight the importance of monitoring autistic adolescent health and targeted interventions to avoid high health burden as early as, or even prior to, 10 years of age. Results also point to the need for policies that promote timely identification of autistic children who may be at an increased risk of developing co-occurring conditions.

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Smith, P.H., Shea, L.L., Rast, J.E., Hino, L.*, Briskey, C., Schendel, D.E. (2025). Autism and medical complexity among children in the U.S. Pediatrics, 155(3), e2024067472

Summary:  Children with medical complexity have multiple or severe chronic conditions that result in significant day-to-day disability, and much higher use of healthcare and service utilization compared to other children. Overlap between autistic children and children with medical complexity is extensive in the U.S. We found that up to 60% of autistic children also have medical complexity, and about 40% of children with medical complexity are also autistic. Children identified as both autistic and medically complex had healthcare expenditures that were significantly greater than children who belonged to only one of these two groups.

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Smith, P.H., Kim, J., Patti, M., Rast, J.E., Lyall, K., Shea., L.L., Sheridan, E., Schendel., D.E. (2025). High support need groups among autistic children and youth in the United States: Prevalence, overlap, and specific support needs. Poster presented at the International Society for Autism Research annual conference, Seattle, WA.

Summary: We examined the prevalence and overlap of four high support need groups among autistic children in the U.S.: 1) medical complexity, 2) serious mental illness, 3) significant disability from intellectual or spoken language disability, and 4) higher socioeconomic support need. Two out of every three autistic children belonged to at least one of these four groups and overlap among the groups was high. Each of these four groups was independently associated with significantly greater specific challenges and support needs, such as unmet service needs, healthcare provider challenges, bullying, and caretaker support needs. Definitions of high support needs should consider multiple sources of need and their high degree of overlap. 

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Smith, P.H., Wright, J., Ventimiglia, J., Schendel, D.E., Lee, B.K., Lyall, K., Mullachery, P., Rast, J.E., Shea, L.L. (2024). Service use and associated expenditures among adolescents with autism spectrum disorder transitioning to adulthood: 2015-2019 update. Poster presented at the International Society for Autism Research annual conference, Melbourne, Australia.

Summary: Among Medicaid enrollees between 2015-2019, autistic adolescents exhibited important patterns of changing healthcare utilization across the transition to adulthood. For example, psychiatric outpatient care utilization remained high across the transition, but became substantially more expensive. In comparison to trends seen using earlier data (2001-2005), outpatient care was generally more stable across the transition to adulthood, potentially indicating improvements in continuity of care since the earlier data were collected.