A 28-Year-Old Medical Student Arrives to the Office with Nervousness

A 28-year-old medical student arrives to the office with nervousness and difficulty concentrating. He has worked part-time as a volunteer fireman and claims that he has struggled to concentrate in class after seeing a critically burned youngster removed from a house fire three weeks ago. The patient began to sweat, tremble, and have difficulty breathing on two occasions: "I felt like my head was spinning and had to rush out of the classroom to recover my breath." He also claims to have difficulty sleeping, to be irritated with friends and family, and to periodically feel as if he is in a dream. "Sometimes I'll be sitting in class and I'll feel like I'm back in the burning room," the patient adds. I can smell the fire and see the child."  He has missed almost half of his classes to avoid being in crowded classrooms and has recently quit his volunteer job.  Which of the following is the most likely diagnosis?

A) Acute stress disorder
B) Adjustment disorder
C) Agoraphobia
D) Depersonalization/derealization disorder
E) Panic disorder
F) Post-traumatic stress disorder