A 39-Year-Old Man Is Brought into the Office by His

A 39-year-old man is brought into the office by his wife, who is concerned about his recent conduct. She states, "He used to be lively and optimistic, but now he appears melancholy and estranged from his family. He is dissatisfied with his job and is having problems making decisions." He has been increasingly paranoid in the last month, believing that his business partner is attempting to murder him. The patient has no history of psychiatric illness. Both his father and grandpa died in their 50s after being hospitalized in long-term care institutions. Physical examination reveals uncontrolled, erratic motions of the left leg. On mental status examination the patient is restless and irritable.  He is convinced that not only his business partner but also the government is out to harm him.  Which of the following is the most likely diagnosis?

A) Brief psychotic disorder
B) Delusional disorder
C) Friedreich ataxia
D) Huntington disease
E) Major depression with psychotic features
F) Parkinson disease
G) Schizoaffective disorder
H) Schizophrenia