Sean describes himself as having hardly ever being happy. he occasionally feels okay, but it never lasts more than a day or so. he has trouble sleeping, doesn't eat much, and feels like nothing will ever change in his life. he says this has been going on for as long as he can remember. the best diagnosis for sean is

Dysthermia

Explanation:

Dysthermia, presently known as PDD stands for Persistent Depressive Disorder, is a mind-set issue comprising of indistinguishable intellectual and physical issues from wretchedness, with less serious yet longer-enduring symptoms. During the late 1970s, this idea was authored by Robert Spitzer as a swap for the expression depressive personality.

Dysthymia.

Explanation:

Dysthymia may be defined as the medical condition of in which the person suffers from the long time depression. This condition is also known as Persistent depressive disorder.

Sean is hardly happy and does not eat much food and is highly depressed. He has been suffering from the depression for the long period of time. The diagnosis for Sean is dysthymia. He must be treated by giving anti-depressant drugs.

Thus, the answer is dysthymia.

c. flammable gases, patient lying in standing water, combustible liquids near the victim