Sleep & Chronophysiology Laboratory

1. M Sleep & Chronophysiology Laboratory The Importance of Sleep and Sleep Hygiene: Practical Clues for the College Student Roseanne Armitage, Ph.D. Professor Director - Sleep and Chronophysiology Laboratory University of Michigan

2. Functions of Sleep M Sleep & Chronophysiology Laboratory SWS – basic sleep drive – rest, recovery & homeostasis Body& blood cell work, immune system, Keep circadian rhythms entrained Stage 2 – maintain vigilance while sleeping REM- Memory consolidation, development of neural connections in childhood

4. RAW DATA STORAGE AMPS DIGITIZEDVALUES PSA or PAA A/D CONVERSION BOARD RESIDENT IN COMPUTER SAMPLING RATE 128-1000Hz OFF-LINE VISUAL SLEEP-STAGE SCORING BETA 12-32 Hz* SIGMA 12-16 Hz ALPHA 8-12 Hz THETA 4-8 Hz DELTA 0.5-4 Hz % ZERO-CROSS % FIRST DERIVATIVE POWER POWER SPECTRA *FREQUENCY BAND WIDTHS DIFFER BETWEEN LABORATORIES

5. REM

6. Stage 4

7. HEALTHY NORMAL CONTROL Awake Move REM Stg 1 Stg 2 Stg 3 Stg 4 SOS: 23:54:00 WUT: 08:51:30 TIME OF NIGHT % REM: 13.3 % STAGE 1: 7.5 % STAGE 2: 57.0 % STAGE 3: 16.9 % STAGE 4: 3.5 SLEEP EFFICIENCY: 96.8% REM LATENCY: 94.5 min SLEEP LATENCY: 7.0 min

8. M Sleep & Chronophysiology Laboratory How much sleep do you need? • Not everyone needs the same amount of sleep Natural short and long sleepers • BUT sleeping less than 6.5 or more than 9 hours is associated with 1.7 x greater mortality & risk of disease.

9. M Sleep & Chronophysiology Laboratory Is it Enough Sleep? • More than 40 % of adults have sleep complaints • 25 % women & 16 % men • # 1 Complaint: Feeling unrested • # 2 Complaint: Difficulty Falling Asleep Among college students 71 % had sleep complaints in 2000 compared to 24 % in 1978

10. M Sleep & Chronophysiology Laboratory How Has Sleep Changed Historically? • Estimated 8-9 hrs in early 20th Century • 7-8 hrs mid 1980s-2002 • College Students: • 1980s reported 7-7.5 hrs • 2002 reported 6-6.9 hrs • Going to bed later is the culprit • Bedtime is 1-2 hrs later than it was 25 yrs ago

11. M Sleep & Chronophysiology Laboratory Napping • 30-50 % of students nap • Nappers have delayed bedtime of >1 hr • 30 % naps >1.7 hrs • Mostly late afternoon naps • Sleep >1 hr less than non nappers

12. M Sleep & Chronophysiology Laboratory Consequences of Sleep Loss • Poor academic performance correlated with insomnia & poor sleep quality • Automobile Accidents: Fatigue is a leading cause • Minor medical Illness: Cold & Flu rates higher in poor sleepers • Circadian dysregulation: Creating Jet Lag in the home environment • Psychiatric Illness: Depression & Anxiety

13. M Sleep & Chronophysiology Laboratory Sleep & Depression • Sleep disturbance > 2 wks is a risk factor for the development of depression • Sleep abnormalities are common symptoms of depression: >80% pts • Often the presenting symptom: Common to notice the sleep problem first

14. M Sleep & Chronophysiology Laboratory Sleep & Depression If sleep problems persist into clinical remission: • Worse clinical outcome and increased risk of relapse in recovering patient • Increased risk of suicide • Daytime fatigue/ reduced functioning • Worry about insomnia may cause further insomnia and anxiety

15. M Sleep & Chronophysiology Laboratory Depression in College Students • Incidence is 2 x greater than general population • Approximately 20 % of students • Often goes undiagnosed and untreated • Increasing risk of another episode

16. M Sleep & Chronophysiology Laboratory Sleep and Depression in College Students • Worsening of depression and sleep problems at exam time (particularly in males) • Minor medical problems 2-4 x more prevalent in depressed students with sleep problems >2 wks duration • Attending University does increase both incidence of sleep problems & depression

17. DEPRESSED PATIENT Awake Move REM Stg 1 Stg 2 Stg 3 Stg 4 SOS: 01:04:00 WUT: 08:51:30 TIME OF NIGHT % REM: 16.9 % STAGE 1: 17.0 % STAGE 2: 46.0 % STAGE 3: 0.0 % STAGE 4: 0.0 SLEEP EFFICIENCY: 79.2% REM LATENCY: 49.0 min SLEEP LATENCY: 6.0 min

18. M Sleep & Chronophysiology Laboratory Sleep & Biological Rhythms • Ultradian <24 hrs • Most common 90 min REM/NREM sleep cycle • Task Performance • Infradian >24 hrs • Lunar cycle • Menstrual cycle

19. M Sleep & Chronophysiology Laboratory Circadian Rhythms • 24 hr rhythms in biology, physiology, mood & performance that are entrained to the light dark cycle • Controlled by the SCN in the hypothalamus • Light is the most potent zeitgeber • Sleep, Cardiovascular Activity, Body Temperature, Hormones, Endocrine & Metabolic Function, Liver & Kidney Function, Gastrointestinal Activity, Immunology

20. 200 600 700 800 900 100 300 400 500 200 600 700 800 900 100 300 400 500 HIGH COHERENCE 100 .99 C3 C4 % Time-In-Frequency 0 EPOCHS LOW COHERENCE .43 100 % Time-In-Frequency 0 EPOCHS

21. Coherence in Girls at High-Risk M Sleep & Chronophysiology Laboratory CUTPOINT= .70 HIGH RISK NC >50 % of girls with extreme low values had 1st episode 3-5 yrs later

22. M Sleep & Chronophysiology Laboratory How Do We Improve Sleep & Depression In College Students? • Education about Sleep • Education about Depression • Clearly identify Biological & Familial Risks • Early Intervention • Development of Easy, Practical Guidelines for Good Sleep Hygiene

23. M Sleep & Chronophysiology Laboratory Good Sleep & Biological Rhythm Hygiene • Maintain regular rise & bed times every night including weekends i.e. 11:00 P.M.-6:00 A.M. ESPECIALLY FOR WOMEN • Very hot bath (~15 min. Duration) 1 1/2 hour before bedtime ESPECIALLY FOR SWS PROBLEMS • Turn down thermostat, no electric blankets Use very dark curtains or use a sleep mask • No napping especially in afternoon or evening

24. M Sleep & Chronophysiology Laboratory Good Sleep & Biological Rhythm Hygiene • Restrict caffeine (not just coffee) 1-2 cups before 10 a.m. • Warm milk 1/2 hour before bedtime • No food or exercise within 2 hrs of bedtime • Avoid time zone changes

25. M Sleep & Chronophysiology Laboratory Schedule for Light Exposure • Early morning bright light will advance the circadian clock i.e make you sleepy earlier • Late afternoon bright light will delay your body clock i.e make you sleepy later • Wear dark glasses to minimize light to retina if your body clock is already shifted • Avoid bright light at night, use incandescent light with the lowest wattage possible.

27. Sleep & Chronophysiology Laboratory M