The modern age is filled with all manner of stress. People stress about work, about love, and about themselves all the time. Man is locked in a constant battle with stress for any number of reasons... sometimes stress can come from absolutely nowhere. Stress works to the detriment of human life, and in fact highly stressed out individuals are expected to die sooner than usual.
In an attempt to rectify this endemic, a scientist developed a drug which he hoped would eliminate stress entirely. Testing proved that it worked, and the subject we no longer have a name for went home and slept easily that night. Little did he know that the treatment was merely temporary, and that it had a very contagious and dangerous side effect. It gave birth to a disease that was transferred through breathing... a disease that fed on stress.
Those infected by the disease begin to mutate into mindless and violent monsters when under intense levels of stress. Their skin turns into oily tar, their veins glow green and blue, and their eyes glow yellow. Most of them lose the ability to speak when transformed into a monster, and become absorbed with the desire to destroy anything in sight. At least, until they finally calm down and they’re no longer stressed out, then they return to normal.
Efforts to develop a cure are progressing, but complicated by the fact that so many people by now have been infected, including medical experts and personnel. Many people still worry about another outbreak... which causes stress... which in turn might cause a transformation... which can stress others out... turning them into monsters... and so on. A vicious cycle of stress and destruction... with seemingly no end in sight.