Clinical Research Directory

Inclusion Criteria: * outpatients 2 to 6 years of age; * males and females who are physically healthy; * diagnosis of autism spectrum disorder based on clinical evaluation and DSM-5 criteria, and confirmed using the Autism Diagnostic Interview-Revised, and the Autism Diagnostic Observation Schedule or Childhood Autism Rating Scale second edition (CARS-2) * care provider who could reliably bring subject to clinic visits, could provide trustworthy ratings, and interacted with subject on a regular basis; * ability of subject to swallow the compound; * stable concomitant medications for at least 2 weeks (4 weeks if patient took fluoxetine); * no planned changes in psychosocial interventions during the open-label trial. Exclusion Criteria: * DSM-5 diagnosis of schizophrenia, schizoaffective disorder, or psychotic disorder not otherwise specified; * prior adequate trial of Esomeprazole; * active medical problems such as unstable seizures, or significant physical illness (e.g., serious liver or renal pathology).