Why Deep Sleep Matters for Teens

As backpacks are packed and alarm clocks get reset for early mornings, back-to-school season is the perfect moment to take a hard look at one habit that affects everything else: sleep. 

We all know that a night of peaceful, restful sleep feels like a gift. Waking refreshed, energized, and ready to attack the day is one of life’s premier feelings. While we may not all experience this daily, we can doubtless all recall, with affection and perhaps a little wistfulness, those occasions when we have had a great night’s sleep.

What is it that makes a night’s sleep “good?” Actually, it is a combination of deep sleep and REM sleep. The two are distinct stages of the sleep cycle, each with unique characteristics and functions. Deep sleep is physically restorative, while REM (Rapid Eye Movement) sleep is mentally restorative. To have a truly “good” night’s sleep, the body needs to experience both of these essential phases to ensure physical and mental rest and restoration.

For teens, deep sleep is a particularly critical restorative necessity. For adolescents ages thirteen to eighteen, deep sleep is especially important for growth, brain development, and emotional regulation. It also regulates stress hormones, strengthens the immune system, and supports positive cognitive development.

Here’s what the research tells us about teen sleep, by the numbers:

• Sleep cycle length: Adults typically cycle through the deep sleep and REM phases every 90 to 110 minutes, completing 4 to 6 cycles per night
• Total nightly sleep: Teens should ideally get 8 to 10 hours of sleep per night
• Deep sleep target: About 20% of a teen’s total sleep should be deep sleep, which works out to 1.5 to 2 hours per night
• Circadian shift: During puberty, circadian rhythms shift up to two hours later, making it increasingly difficult for teens to fall asleep before 11:00 p.m.

Of course, challenges exist for teens, even those who aspire to get more sleep. Blue light from phones and other devices compounds the problem by suppressing melatonin, the hormone that signals the brain it’s time to sleep.

Given the critical benefits provided by deep sleep, it’s worth looking for ideas to give teens access to these benefits. Here are some suggestions, all of which we promote at St. Luke’s.

• Maintain the same bedtime, even on weekends, if possible
• Build in a tech free wind down: spend the last thirty to sixty minutes before sleep without devices
• Try a white noise machine to support wind down
• Avoid caffeine after noon
• Get regular exercise: physical activity earlier in the day helps teens fall asleep faster and increases the amount of time spent in deep sleep

While these tips may seem straightforward, and the benefits of deep sleep are undeniably positive for teens, sleep deprivation in adolescence is a widespread and serious issue. Clinical research continues to show that teens who lack this specific stage of sleep often exhibit a combination of immediate behaviors, “red flags,” and long-term physical health declines and changes, including increased irritability and depression, increased impulsivity, risk-taking, hyperactivity, and anxiety. Memory impairment, slowed reaction times, more frequent illness, and physical aches and pains are also possible.

It’s time to tackle sleep as the final frontier. Why not talk with your teen about their honest nighttime routine? Share the significant benefits that deep sleep can provide at little cost. A few questions to get the conversation started:

• What does your nighttime routine actually look like, including the last hour before bed?
• Do you recognize any of the side effects related to a lack of deep sleep, like irritability, trouble focusing, or getting sick more often?
• Would you like to see those symptoms decrease or disappear?
• What’s one small change you’d be willing to try this week?

Following a few simple steps could bring dramatic results, no special occasion required to give sleep the attention it deserves.