Comment by dxyms

According to the article on question: The effects of caffeine intake on the quality and quantity of sleep depend on the timing of its consumption. More specifically, caffeine consumed in the evening hours prolongs sleep latency10,11,12,13,14, reduces total sleep time (TST)10,11,12,14,15, shortens deep sleep10,12,13,14,15, and decreases electroencephalographically (EEG)-derived slow-wave activity (SWA)10, while activity in the sigma range is increased10.