REM sleep is vital for normal functioning. Every time we fall asleep, we get in the REM sleep firstly.
Long term (up to almost 60 days) experiments made with guinea pigs, depriving them of REM sleep led them to death.
Experiments performed in people have shown that REM sleep-deprived people had a REM Rebound, and an increase in the frequency of awakening attempts to take the subject away from REM sleep was necessary.
