Trajectories of Seizures, Medication Use, and Obesity Status into Early Adulthood in Autistic Individuals and Those with Other Neurodevelopmental Conditions

Background: Physical and psychiatric health conditions affect the lives of many autistic adults. However, relatively little is known about individual trajectories in autistic individuals' physical and mental health from adolescence to adulthood. Methods: This study uses a well-characterized longitudinal sample (n = 253) to investigate rates of seizures, medication use, and obesity, from early adolescence (age 10 years) into adulthood (age 30 years). Within this sample, 196 participants were diagnosed with autism spectrum disorder (ASD), whereas the remaining 57 participants never received an ASD diagnosis, but, rather, were diagnosed with other neurodevelopmental conditions. Data were collected through parent report questionnaires and in-person interviews and assessments. Results: Seizure onset continued well into adulthood, with two individuals experiencing their first seizure at the age of 25 years. Seizures and neuropsychiatric medication use were both higher for those with lower intelligence quotient (IQs). In addition, medication use increased over time for these individuals, whereas those with higher IQs saw a reduction in medication use with age. Between the ages of 15 to 30 years, the predicted probability of medication use increased from 82% to 88% for those with lower IQs and decreased from 37% to 13% for those with higher IQs. Collectively, almost 70% of all participants in this study were classified as either overweight or obese. Body mass index (BMI) increased throughout adulthood, especially for those with higher IQs. The steepest increase in BMI over time occurred for those with higher IQs who also took antipsychotic medications. Conclusion: Overall, continued risk for developing seizures, high rates of neuropsychiatric medication use, and significant and increasing rates of obesity from adolescence to adulthood underscore the importance of monitoring health issues in autistic individuals and those diagnosed with other neurodevelopmental conditions throughout the lifespan.