A 30-year-old man is brought to the emergency depament by police, who arrested him because he was in the parking lot of a local mall, yelling "I am a golden god" as he stepped in front of moving cars. When questioned about his identity, he talks incessantly in a rapid fashion and threatens to "unleash God's wrath on those who do not submit." He repos that he has not slept in a week, and does not need sleep. He has spent the last week preparing for a secret government mission that only the president knows about. When asked if he ever hears God talking to him, he says, "Of course not, I am God!" Police repo that he has had several prior arrests for reckless driving and lewd acts. On examination, he is disheveled and malodorous. It is nearly impossible to get any fuher history, as he rapidly paces about and mutters, "I must go, I must go" over and over again.Which of the following is the most likely preliminary diagnosis?