Final answer:
Delusions and hallucinations are most commonly associated with schizophrenia, a severe mental illness requiring antipsychotic medications for treatment.
Step-by-step explanation:
Delusions and hallucinations are most commonly associated with schizophrenia, which is a serious mental illness characterized by symptoms such as the inability to differentiate between reality and imagination, inappropriate emotional responses, difficulty thinking, and problems with social situations. Schizophrenia affects approximately 1% of the population in the United States, with many patients being diagnosed in late adolescence or their early 20s. The treatment often involves antipsychotic medications that block dopamine receptors to decrease dopamine neurotransmission in the brain. These symptoms are not typically associated with somatoform disorders, conversion hysteria, or mania.