How does caffeine affect sleep latency and total sleep time?

How does caffeine affect sleep latency and total sleep time?

• A. Decreases sleep latency and increases total sleep time
• B. Has no effect on sleep latency and total sleep time
• C. Increases sleep latency and reduces total sleep time
• D. Improves sleep architecture regardless of timing

Answer: (C)

Caffeine acts as a stimulant by blocking adenosine receptors in the brain, which normally promote sleepiness. By reducing sleep pressure, it makes it harder to fall asleep, increasing sleep latency. It also tends to shorten the total sleep time, especially when consumed close to bedtime, because the stimulating effects can spill into the night and disrupt ongoing sleep. In short, caffeine tends to delay sleep onset and reduce how long you sleep. The other statements don’t fit this mechanism: caffeine doesn’t reliably shorten latency or lengthen sleep duration, and it doesn’t universally improve sleep architecture regardless of timing.

Caffeine acts as a stimulant by blocking adenosine receptors in the brain, which normally promote sleepiness. By reducing sleep pressure, it makes it harder to fall asleep, increasing sleep latency. It also tends to shorten the total sleep time, especially when consumed close to bedtime, because the stimulating effects can spill into the night and disrupt ongoing sleep. In short, caffeine tends to delay sleep onset and reduce how long you sleep. The other statements don’t fit this mechanism: caffeine doesn’t reliably shorten latency or lengthen sleep duration, and it doesn’t universally improve sleep architecture regardless of timing.