“You Snooze, you lose” Whose Side are you on “You Snooze, you lose” Whose Side are you on? The Magical Mystery Sleep Tour across Age, the Day, and Through the Ages Professor Leon Lack, PhD, MAPS School of Psychology Adelaide Institute for Sleep Health, Repatriation General Hospital

This belief about sleep is not true! What is the normal sleep pattern? This is the concept held by most of the public. Light Moderate Deep Deeper A solid 7-8 hours of sleep. None of them showed an awakening from sleep. This belief about sleep is not true! © Leon Lack

Let’s explore the real nature of sleep Let’s explore the real nature of sleep. Flinders University Sleep Lab at sunset Office Sleep Lab

Inside Lack’s Sleep Laboratory?

The stages of sleep vary dramatically and rapidly across the sleep period. Light Moderate Deep Deeper Awakenings are a normal part of the sleep period! What function would they or did they serve? © Leon Lack

Why is this knowledge important? Can reduce worry and help treat insomnia. Cognitive therapy Awakenings become more frequent and insomnia more prevalent with age. This correct knowledge can help prevent the development of insomnia. Inoculate the brain against insomnia. Can this mental drug be improved?

Sleep Through The Ages? Virginia Tech University, USA

A. Roger Ekirch, Sleep Historian History of every day behaviours like sleep not easy to investigate. Picked up enough clues to construct a picture of our changing sleep behaviour.

A. Roger Ekirch, Viginia Tech University, Sleep Historian Sleep Through the Ages ? A. Roger Ekirch, Viginia Tech University, Sleep Historian 1st 2nd ? Prior to yr 1800 Mid 1800s Late 1800s Early 20th Century Today What caused these changes?

Is there an endogenous dual sleep tendency still present?

The Sleep Cultural Conflict The sleep minimizers (misers) Some notable persons (Edison, Churchill, Thatcher, Rudd, Clinton, Trump, Type A personalities) Possible REM sleep loss magnifies these types.

The Sleep Cultural Conflict – The Sleep Boosters National Sleep Foundation USA Sleep Health Foundation Australia

Sleep Across Age Quick decrease of habitual sleep time around time of puberty. Do the biological changes at puberty contribute to this? May also be social causes.

Bill Dement’s Sleep Camp run by Mary Carskadon in the 1980s at Stanford University

Findings from the Sleep Camp Normal children from age 8 to adolescents aged 18 years. Long scheduled sleep opportunities (10 hours) Children slept about 9.2 hours, same as habitual home sleep. Adolescents slept about 9.0 hours, at least an hour longer than habitual home sleep during school year. Anecdotally they felt rested at Sleep Camp. Many adolescents are probably chronically sleep restricted. Contributing to this may be increased academic demands, social demands, technological entertainments and distractions, increased eveningness, circadian phase delay, and decreased rate of accumulating sleep drive across the day. (present research with Mary and Michael Gradisar)

Effects of increasing age on sleep Steady decline of deep sleep Increase of light stage 1 sleep Gradual increase of number and length of awakenings Increase of time in bed from about 60 years Increase in daytime napping Do these changes of sleep impair daytime feelings and functioning? Does sleep need decrease with age?

Sleep Need Determined for Elderly Healthy participants in their 70’s compared with those in their 20’s. (Klerman & Dijk, 2008) Habitual TST was 6.5 versus 8.0 hours. Unlimited sleep opportunity TST (sleep “need”) was about 7.5 and 9.0 hours respectively. Healthy people usually sleep about an hour less than their “need”. Is this detrimental? Older people get 1.5 hours less and “need” 1.5 hours less sleep than young people.

1. Awakenings are a normal (once necessary?) part of the sleep period. 2. Healthy older sleep is lighter and shorter with no detrimental effects on daytime functioning and feelings. 3. Getting the 90-minute sleep cycles is all that matters! 4. With age we have a 20% reduction in metabolic rate, need 20% fewer calories, and need 20% less sleep.

Australia national sleep survey Sleep Loss 1.5 hours Sleep Loss 0.3 hours Australia national sleep survey

Frequent Difficulties (3 or more times/week) with Aspects of Sleep

Daytime Consequences So, most of us would benefit by getting a bit more sleep. But it also matters when we attempt sleep. Why?

The Body Clock The central circadian time giver is a small nucleus in the hypothalamus, the Supra-chiasmatic Nucleus (SCN).

Normally Timed Individual Wake Maintenance Zone Wake Up Zone   Sleep? Sleep? Core Temperature Optimal Sleep Period Circadian “Bed” Sleep Propensity Tmin Melatonin 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 PM Midnight AM Noon TIME © Leon Lack

The Endogenous Circadian Clock Most of us have our internal clock tick over more slowly than the earth’s rotation. The average period length is 24.2 hours. Tendency to delay sleep and awakening by about 12 minutes each day. Evening types tend to delay 20 minutes each day. Delayed sleep/wake phase disorder patients delay by 34 minutes. Free running patients delay by almost an hour.

Bright Light Can Re-Time the Body Clock

Re-timer.com

Sleeping-in on the Weekend? Sleep pressure accumulates during the week from inadequate sleep. The weekend or free time is seen as opportunity to pay off this sleep debt by sleeping-in late. Sleeping-in late removes the role that light has in breaking the delay drift of rhythm. Getting to sleep on Sunday night becomes difficult and the cycle continues. Will the shift to Eastern Time exacerbate this problem?

Conclusions Normal sleep is a roller coaster with awakenings. Awakenings have been normal through history. Insomnia sufferers take heart. Cultural clash between misers and boosters. Probably most of us would be benefited by more sleep. Body clocks tend to delay. Stop it with morning light.