Which daytime consequence is commonly associated with adolescent sleep phase delay on school days?

Which daytime consequence is commonly associated with adolescent sleep phase delay on school days?

• A. Daytime sleepiness
• B. Improved mood
• C. Increased energy
• D. Fast reaction times

Answer: (B)

Adolescents naturally shift toward later bedtimes, but early school start times force them to wake up sooner than their bodies are ready for. That mismatch means they don’t get enough sleep on school days, so daytime sleepiness becomes the most common daytime consequence. When sleep is restricted, alertness drops, making it harder to stay focus and function well in class. The idea that mood would improve isn’t supported by how sleep loss affects mood—sleep deprivation more often worsens mood rather than enhances it. Likewise, increased energy or very fast reaction times would be unlikely with insufficient sleep, as fatigue tends to slow both energy and reaction speed. So daytime sleepiness best captures what typically happens on school days with a delayed sleep phase.

Adolescents naturally shift toward later bedtimes, but early school start times force them to wake up sooner than their bodies are ready for. That mismatch means they don’t get enough sleep on school days, so daytime sleepiness becomes the most common daytime consequence. When sleep is restricted, alertness drops, making it harder to stay focus and function well in class. The idea that mood would improve isn’t supported by how sleep loss affects mood—sleep deprivation more often worsens mood rather than enhances it. Likewise, increased energy or very fast reaction times would be unlikely with insufficient sleep, as fatigue tends to slow both energy and reaction speed. So daytime sleepiness best captures what typically happens on school days with a delayed sleep phase.