A 32 year old male presents claiming that his father is trying to kill him by poisoning his food. The patient reports poor sleep for the past 5 weeks as well as auditory hallucinations. He has become increasingly withdrawn and suspicious over the past 2 months and is talking to himself. What is the appropriate diagnosis?
1) Schizoaffective disorder
2) Delusional disorder
3) Brief psychotic disorder
4) Schizophreniform disorder
