The Lifecycle of Sleep

I'm Dr. Shelby Harris, a licensed clinical psychologist who specializes in behavioral sleep medicine. Today, I'll be taking you on a journey through the dynamic sleep habits and changes we experience at every stage of our lives so you can get a better sense of your own sleep needs at any age. Let's dive right in. As any parent knows, a newborn baby's sleep schedule is very sporadic. Their sleep-wake cycle is inconsistent because their circadian rhythm, or our 24-hour internal body clock, hasn't been established yet, so young infants cycle constantly between sleeping and eating, with sleep taking up 14 to 17 hours each day. After the first few months of life, older infants start experiencing longer sleep blocks with a few naps sprinkled in throughout the day. As they progress through the toddler stage and into school age, and around five to six years old, many kids have actually stopped naps entirely. By now, they start having one continuous and consolidated sleep block at night, just like adults do. For kids age 6 to 12, their sleep-wake cycle is naturally on the earlier side, meaning they often go to bed early and wake up early. Depending on the specific age, this group is getting 9 to 11 hours each night, and they should be sleeping like a log. This is because kids experience a lot of high-quality stage 3, 4 non-REM sleep, also known as deep sleep, during the first few hours of falling asleep. In this stage, human growth hormone is released into the bloodstream from the brain's pituitary gland. This hormone is responsible for bone and muscle growth, so it means kids are literally growing while they sleep. Kids also need to sleep to help boost their mental functions, from brain development to memory consolidation and emotional processing. To optimize sleep for 6 to 12 year olds, make sure that they're practicing good sleep hygiene. This age group is notorious for testing limits and trying to stall. So it's very important that they have a consistent bedtime and wake time. Poor sleep hygiene can negatively impact their alertness, cognition, mood, and might even exacerbate night terrors and sleep walking, which can be seen in this demographic. Now we all know teenagers can have wacky sleep schedules. They might stay up all night and sleep past noon if they could. But did you know that there's a scientific reason for that? Melatonin is a hormone made naturally in our bodies, mainly from our brains' pineal gland, and that gets secreted at nighttime to help signal sleep onset. Studies conducted by Dr. Mary Carskadon, a prolific researcher in the sleep field, measured melatonin levels in saliva and found that teens produce melatonin at later times then younger kids. So it's actually natural for teens to go to bed later and then wake up later since our circadian rhythm is shifted back. The ideal sleep range for teens is 8 to 10 hours per night, but unfortunately, one of...