Amusing article :) -- but in all seriousness I have been subject to many of the effects of caffeine overdose. Some days I might drink over 800 mg (the rough equivalent of 8 cups of coffee), via energy drinks, soda, and/or espresso. My stomach suffered a lot from the acidity, including acid reflux and damage to my stomach lining (mostly from soda - also, inconclusively, I suspect my appendicitis may have been related to this abuse). I would undergo "panic attacks" - i.e. adrenaline rushes, especially after exercising or during the summer and sometimes sweat like crazy in public. My sleep hours became backwards since I was self-employed - I would wake up at night and sleep through the day most of the time. I even tried quitting once for about a month, but could not handle the constant fatigue. All in the name of keep my mental gears turning to be a "better" programmer :)