A 48-year-old man is brought to the ED by family members who state that the patient has remained home-bound for weeks, sleeping for many hours, and appears disheveled. The patient states that he is “fine” and denies any medical symptoms. Initial vitals include HR of 77 beats per minute, BP of 118/55 mm Hg, and RR of 12 breaths per minute with oxygen saturation of 97% on room air. The patient is afebrile with an unremarkable physical examination. He denies any chest discomfort, difficulty breathing, constipation, cold intolerance, weakness, weight changes, or pain. The patient reports that he has had difficulty concentrating, a decreased appetite, and excessive sleeping patterns. The family reports that this has happened before, but that his symptoms selfresolved and were not nearly as severe. Given this patient’s presentation, which of the following is the most likely etiology of this patient’s symptoms?

a. Hypothyroidism

b. Major depressive episode

c. Diabetes mellitus

d. Subdural hematoma

e. Cushing syndrome