The psychiatric-mental health nurse practitioner is treating a 6-year-old boy with autism spectrum disorder (ASD) who has not responded to 9 months of psychosocial therapy and continues hitting his younger brother. What is the most appropriate treatment for the PMHNP to initiate at this time?

Choice A reason: Sertraline, an SSRI, is primarily used for anxiety and depression and is not indicated for aggression in children with ASD. Choice B reason: Carbamazepine is an anticonvulsant used for mood stabilization or seizure disorders but is not first-line for irritability or aggression in ASD. Choice C reason: Risperidone is FDA-approved for the treatment of irritability, aggression, and behavioral disturbances in children with ASD, making it the most evidence-based pharmacologic choice for this patient. Choice D reason: Venlafaxine, an SNRI, is used for depression and anxiety but has limited evidence for aggression management in pediatric ASD.