Are you driving yourself crazy because you have too much free time? Okay, maybe people at work are driving you crazy. One way or another, Stanford neuroscientist Robert Sapolsky believes you are prone to think yourself sick.

Sapolsky does not single out you specifically. His observation applies to all people, apes and monkeys more or less equally. Primates have the same stress response system as many other animals, such as fish, reptiles and birds. We just have the ability to create stress for ourselves. This wasn't always the case. Say you are dragging your knuckles through the forest, when a mountain lion charges you. Without thinking about it, you have climbed a tree to escape danger. At the instant you recognized the danger, glands above your kidneys squirted epinephrine (adrenaline) into your blood stream. This powerful hormone raised your heart rate and kicked fuel, glucose, out of your liver.

Mountain lions no longer threaten us on a daily basis, so we have to make up threats. These psycho-social threats, real or imagined, have the same effect as proximity to physical danger, Sapolsky told the annual American Association for the Advancement of Science last week in San Francisco.

People and our simian relatives, with our big brains, are at greater risk of developing heart disease, high-blood pressure and other chronic stress diseases. We think ourselves into a biological fight-or-flight scenarios all the time. It's not healthy. Which is why for $3,700 you can throw yourself before a mountain lion.