nearly 48 hours..i was on the brink of collapsing by the time i finally got to sleep..trust me mate, u don't want to go 2 days without sleep..it can drive u insane..i couldn't sleep that time coz the Zoloft i was taking messed with my sleeping cycle..horrible..these are some stuff i got from wikipedia on sleep deprivation that i thought was really interesting:
As a cause of death
There are no documented cases of a healthy human dying from total sleep deprivation (excluding accidents), aside from those suffering from Fatal Familial Insomnia. In carefully monitored experiments, several normal research subjects stayed awake for 10 days. While they all experienced cognitive deficits in memory, concentration, etc, none of them experienced serious medical, neurological, physiological or psychiatric problems. Total sleep deprivation in rats leads to death in around 28 days. Death occurs later if only REM sleep is eliminated. In humans, extended sleep deprivation causes microsleep sessions to develop. A person who has fatal familial insomnia may die after several months with no sleep at all; people without this condition may experience dementia or develop permanent personality changes within the first few weeks.
Effects on the brain
A 2000 study by the UCSD School of Medicine and the Veterans Affairs Healthcare System in San Diego, used functional magnetic resonance imaging (fMRI) technology to monitor activity in the brains of sleep-deprived subjects performing simple verbal learning tasks. The study showed that regions of the brain’s prefrontal cortex (PFC) displayed more activity in sleepier subjects. Depending on the task at hand, in some cases the brain attempts to compensate for the adverse effects caused by lack of sleep. The temporal lobe, which is a brain region involved in language processing, was activated during verbal learning in rested subjects but not in sleep deprived subjects. The parietal lobes, not activated in rested subjects during the verbal exercise, was more active when the subjects were deprived of sleep. Although memory performance was less efficient with sleep deprivation, greater activity in the parietal region was associated with better memory.
As a treatment for depression
Recent studies show sleep deprivation has some potential in the treatment of depression. 60% of patients, when sleep-deprived, show immediate recovery, with most relapsing the following night. The incidence of relapse can be decreased by combining sleep deprivation with medication. Incidentally, many tricyclic antidepressants happen to suppress REM sleep, providing additional evidence for a link between mood and sleep