BACKGROUND Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental condition associated with debilitating comorbidities [e.g. , aggression, irritability, gastrointestinal (GI) issues]. Medical management primarily targets these symptoms, as no drug is Food and Drug Administration-approved for core social-communication deficits. AIM To synthesize the efficacy and safety of five major pharmacological classes and evaluate the emerging evidence for biomarker-driven (precision medicine)