Final answer:
Antipsychotics are the medication that Vance would most likely benefit from as they are used to manage psychosis, including delusions, hallucinations, and disordered thought.
Step-by-step explanation:
The medication that Vance would most likely benefit from is antipsychotics. Antipsychotics are primarily used to manage psychosis, including delusions, hallucinations, and disordered thought, which aligns with Vance's therapist's belief that he is psychotic. Antipsychotics are commonly used to treat schizophrenia and bipolar disorder, among other psychotic disorders.