SLEEP : Food for the brainMs Bovdis

Sleep-wake cycle during adolescence

What is your sleep cycle like?

How long do you sleep for?

How long should you be sleeping for?

What happens when you don’t get enough sleep?

Source: Grapheast

Stages of sleep• There are 4–5 continuous sleep cycles per night • Each sleep cycle (REM & NREM) lasts 80–100

mins • Approximately 80% of adult sleep is NREM

Sleeps patterns over a lifespan

How much sleep do you need each night?

Adolescent sleep needs & patternsPhysiological patternsAdolescents need as

much sleep as they did as pre-adolescents (8.5 to 9.25 hours each night)

Daytime sleepiness increases.

Adolescents’ sleep patterns undergo a phase delay, that is, a tendency toward later times, for both sleeping and waking. This is called the sleep-wake cycle shift.

Studies show that the typical High School student’s natural time to fall asleep is 11.00pm or later.

The ‘biological clock’, an inbuilt timing system goes through a cycle (every 24 hrs) during which hormones are produced to control body functions. This is known as the circadian rhythm and the sleep hormone melatonin causes us to feel sleepy.

Sleep-wake cycle shiftThis shift in the onset

of the sleep period (sleep phase onset) also means that there is a biologically driven need to sleep one to two hours longer.

Early school or work starts don’t allow the adolescent to sleep in and have the additional sleep that would naturally occur.

This nightly sleep loss can accumulate as a sleep debt; that is, sleep that is owed and needs to be made up. For example a nightly sleep debt of 90 minutes between Monday and Friday would add up to a total sleep debt of 7 ½ hrs. On the weekends adolescents will often sleep to make up their sleep loss.

Cont...This cycle is linked to external cues in the environment

such as:The presence or absence of sunlightAlarm clocksMeal timesTelevisionThe amount of the hormone melatonin present in the blood

stream influences how sleepy a person becomes- higher melatonin levels result in greater sleepiness.

The amount of melatonin that is secreted varies with the level of light in the environment.

Less melatonin is secreted in daylight and as night falls, the reduction in illumination triggers the pineal gland (near the hypothalamus at the centre of the brain) to release more melatonin which explains why we are more sleepy at night.

Sleep tips for adolescence1. A lack of sleep can make you look tired and

feel depressed , irritable and angry. Learn how much sleep you need to function at your best. Most adolescents need between 8.5 and 9.25 hours of sleep each night .You should awaken refreshed, not tired.

2. Establish a regular bedtime and wake-time schedule and maintain this schedule during weekends and school and work vacations. If you must go off your schedule avoid delaying your bedtime by more than one hour.

Sleep tips continued...Get into bright light as soon as possible in the

morning, but avoid it in the evening. (Light helps to signal to the brain when to wake up .)

In the afternoon stay away from caffeinated coffee, coke as well as nicotine, which are stimulants.

Avoid alcohol. It disrupts sleep.Relax before going to bed! Avoid heavy

reading, studying and computer games within one hour of going to bed. Don’t fall asleep with the television on-flickering light and stimulating content can inhibit restful sleep.

Consequences of poor sleep in adolescenceAustralian

psychologist and researcher Michael Gradisar (2009) has found that adolescents should sleep for around 8 or 9 hours for optimal brain functioning; anything less disadvantages short-term memory and other mental processes.

Negative moods (eg anger, sadness and fear), difficulty controlling emotions and behaviour problems.

Increased likelihood of stimulant use (including caffeine and nicotine), alcohol and similar substances.

Low grades and poor school performance (those students who are getting “C’s” are getting less sleep, have later bedtimes than students reporting higher grades.)

• Circadian rhythm is linked to external cues such as daylight, meal times, and alarms. Hormones are also produced in a cyclical pattern to control bodily functions such as the release of melatonin.

• But how is a sleep-wake cycle different during adolescence?

• Adolescents typically have irregular sleep patterns

• Adolescence shifts the body clock forward 1-2 hours resulting in sleep phase onset

• This results in an accumulation of a sleep debt.

Sleep-wake cycle during adolescence

Purpose of sleepRestoration theory proposes that NREM sleep restores and repairs the body, while REM sleep restores the brain and is involved in processes of memory and learning.

Survival theory proposes that sleep conserves energy and protects organisms from danger. Predators sleep more than their prey, but smaller animals who can hide easily also sleep more.

Are you getting enough sleep?NOW - Complete the “Are you sleep deprived?”

Activity sheet.

SCORING:To score this questionnaire count the number

of times you circled YES

How to interpret your score.....4 or lessYou are getting an

adequate amount of sleep and are not showing signs of sleep deprivation

5 or 6You are getting an

adequate amount of sleep on most days but some days you don’t get enough and that may cause you to be less than 100% alert on some activities.

7 or 8You are showing evidence

of sleep deprivation that may cause a noticeable reduction in your efficiency at school or work and your ability to finish your required activities on time. Look out for simple errors and short episodes of inattention. You will slip up occasionally, act clumsily or miss important detail.

Sleep deprivationPartial Deprivation Effects

(having less sleep than normally required) are:Tiredness, lack of energy, lapses in concentrationA low level of motivationImpaired motor skillsIrritability and occasional headaches.Note: There is a decline in the ability to perform

cognitive tasks and people have slower reaction times on motor tasks

Sleep deprivationTotal Sleep DeprivationDepression, hallucinations, delusions (false

beliefs) and paranoia (a false belief that others want to harm you).

Physiological effects are hand tremors, drooping eyelids, difficulty focusing the eyes, lack of energy and strength, slurred speech and an increased sensitivity to pain.

After 3 or 4 days of total sleep deprivation people automatically drift into microsleeps.

Enjoy camp but go to sleep by 10pm!