Abstract
Adults with intellectual and developmental disabilities (IDD) experience significant health disparities and face persistent barriers to high-quality care. Psychotropic medications are prescribed at high rates among adults with IDD, often off-label and in the absence of a documented psychiatric diagnosis, raising longstanding concerns about their use as a substitute for adequate behavioral support rather than as clinically indicated treatment. The structural mechanisms driving variation in psychotropic medication prescribing, however, have received limited systematic attention. Understanding these mechanisms is consequential, as they point toward policy levers capable of improving care quality, centering the needs and preferences of people with IDD, and reducing potentially inappropriate prescribing for one of Medicaid's most clinically complex and socially vulnerable populations.Using Transformed Medicaid Statistical Information System (T-MSIS) Analytic Files spanning all fifty states and Washington, DC, I examined three interrelated projects organized around a set of hypothesized structural pathways connecting Medicaid long-term services and supports (LTSS) and Home- and Community-Based Services (HCBS) organization, workforce conditions, and external shocks to psychotropic medication prescribing patterns among adults with IDD. I drew on Cawley and Grabowski's factor substitution in health care production framework and Andersen's behavioral model of health care utilization to ground my analyses theoretically.
My first project examined racial, ethnic, and residential disparities in psychotropic medication prescribing using a cross-sectional multi-state sample of adult Medicaid beneficiaries with IDD in 2019. My second project investigated associations between state IDD service system characteristics, including fiscal investment in community services and direct support professional (DSP) compensation, and psychotropic medication prescribing in congregate HCBS and intermediate care facilities for individuals with intellectual disabilities (ICF/IID). My third project characterized longitudinal trends in psychotropic medication prescribing across residential settings before, during, and after the COVID-19 pandemic using interrupted time series analyses.
Findings across all three projects converge on a coherent picture: psychotropic prescribing disparities in IDD service systems are not random, and they are not immutable. They are shaped by the structural conditions under which care is organized and delivered, including residential setting type, racial and ethnic composition, DSP workforce stability, and Medicaid reimbursement adequacy. For state and federal policymakers seeking to improve care quality and advance equity for people with IDD, this dissertation provides new evidence on the structural mechanisms that produce prescribing variation and identifies the policy leverage points at which meaningful intervention is most feasible.