This narrative review intends to serve as an overview of the pharmacology of aripiprazole with focus on its effects on muscarinic pathways and the Dopamine D2 Receptor (DRD2), the implications of that pharmacology for antipsychotic polypharmacy in the treatment of inpatient high-acuity and treatment-resistant psychosis, and its clinical utility particularly as an LAI when used in conjunction with other antipsychotics. Here, DRD2 is linked to psychotic disorder.