Prevalence of Co-occurring Mental, Neurodevelopmental and Neurological Conditions in Medicaid Beneficiaries With Autism.

PURPOSE: As more children with autism enter adulthood, updated data on co-occurring conditions throughout the lifespan are needed. We examined mental, neurodevelopmental and neurological (MNN) conditions among people with and without autism overall and by demographics.

METHODS

Using Medicaid claims data for beneficiaries aged ≥ 1 year enrolled during 2020, we identified autism and MNN diagnoses using ICD-10 codes. Adjusted prevalence ratios (aPRs) in beneficiaries with versus without autism were calculated using log-binomial models.

RESULTS

Among 993,965 beneficiaries with autism, attention-deficit-hyperactivity and conduct disorders (ADHD/CD, 30.5%), intellectual disabilities (ID, 20.4%), and anxiety disorders (19.3%) were most common. Prevalence of every condition except ADHD/CD increased with age and was higher in females. For most conditions, prevalence was lowest in American Indian/Alaska Native (AI/AN) and Hispanic individuals. Every condition except alcohol/drug use disorders was significantly more prevalent in those with autism; aPRs ranged from 1.8 (depression) to 21.2 (ID). APRs were higher in middle and older ages for neurodevelopmental conditions, in children and adolescents for mental and neurological conditions, and in women for neurodevelopmental and neurological conditions. AI/AN beneficiaries had the highest aPRs for nearly all conditions.

CONCLUSION

Among publicly-insured individuals, MNN conditions were more common in beneficiaries with than without autism across the lifespan, in both sexes and across racial/ethnic groups. Demographic variation may reflect underdiagnosis of autism in previous generations and females, respectively, and less access to mental health services in some racial/ethnic groups. Screening for ADHD and mental health disorders in youth and adults with autism may improve health outcomes. Screening for ADHD and mental health disorders in youth and adults with autism may improve health outcomes.