did you actually RTFA?
LONG TERM sleep deprivation. As in your lifestyle - swing shifters, etc. Not the occasional amphetamine binge, or caffeine fueled cram/D&D/gaming session.
never mind the actual experiment they conducted where they found neurons destroyed in the brains of mice that were kept on a wonky sleep schedule.
our bodies are TUNED to be active during the day, sleep at night.
probably contributes to jetlag.. see http://en.wikipedia.org/wiki/C... "Although circadian rhythms are endogenous ("built-in", self-sustained), they are adjusted (entrained) to the local environment by external cues called zeitgebers, commonly the most important of which is daylight."