A 36 year-old man presents to the emergency room asking for removal of software implanted in his body by his neighbor. He tells you that his x-wife is hiring this neighbor to spy on him. For the last 6 years he has been hearing them talking about him and all details of his life. He lives alone and he does not have any friends. He has no kids and one sister who do not visit him anymore since he accused her of spying on him. His physical examination and laboratory studies are unremarkable. Drug test is negative. What is the most likely diagnosis?
A-Brief psychotic disorder
B-Bipolar disorder
C-Major depressive disorder
D-Schizophrenia
E-Schizophreniform disorder