M 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

Functions of Sleep 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 M M Sleep & Chronophysiology Laboratory

AMPS POWER SPECTRA % ZERO-CROSS % FIRST DERIVATIVE POWER *FREQUENCY BAND WIDTHS DIFFER BETWEEN LABORATORIES A/D CONVERSION BOARD RESIDENT IN COMPUTER SAMPLING RATE Hz BETA12-32 Hz* SIGMA12-16 Hz ALPHA 8-12 Hz THETA 4-8 Hz DELTA0.5-4 Hz PSA or PAA RAW DATA STORAGE DIGITIZED VALUES OFF-LINE VISUAL SLEEP-STAGE SCORING

REM

Stage 4

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

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. M 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 M M Sleep & Chronophysiology Laboratory

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

Napping  % 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 M 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 M 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 M M Sleep & Chronophysiology Laboratory

Sleep & Depression  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 If sleep problems persist into clinical remission: M 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 M 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 M M Sleep & Chronophysiology Laboratory

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

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

HIGH COHERENCE LOW COHERENCE EPOCHS % Time-In-Frequency C3 C

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

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 M 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 M M Sleep & Chronophysiology Laboratory

 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 Good Sleep & Biological Rhythm Hygiene M 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. M M Sleep & Chronophysiology Laboratory

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