A patient experienced the sudden onset of confusion, firm beliefs of being spied on, and auditory hallucinations. The patient did not experience racing thoughts, elevated or depressed mood, or changes in energy level. The patient was hospitalized after 2 days of symptoms, aripiprazole was started, and symptoms fully resolved within 3 weeks of symptom onset. There is no history of a recent illness or substance use. About 1 month ago, the patient's partner filed a divorce petition. Past psychiatric and medical history are unremarkable. Which of the following is the most likely diagnosis?
