What sleep phenomenon is common in adolescence, involving later bedtimes and waking times?

• A. Delayed sleep phase; shift in circadian rhythm
• B. Narcolepsy
• C. Sleep apnea
• D. Night terrors

Answer: (A)

The key idea here is a shift in the timing of the body's internal clock that commonly occurs during adolescence. Teens often experience a later release of melatonin, the hormone that helps trigger sleep, so their biological night starts later. This makes them naturally fall asleep later and also want to wake up later, which clashes with early school start times and can lead to daytime sleepiness if schedules aren’t adjusted. This pattern is known as a delayed sleep phase, reflecting a circadian rhythm shift specific to adolescence.

The other options don’t fit this pattern. Narcolepsy involves sudden, uncontrollable sleep attacks and daytime sleepiness that isn’t tied to a delayed night-time onset. Sleep apnea features breathing interruptions during sleep and is usually associated with snoring and daytime fatigue regardless of bedtime. Night terrors occur mainly in young children and involve abrupt, frightening awakenings, not a consistent shift in sleep timing during adolescence.