Sleep is a psychobiological phenomenon i.e. it involves
- (1) How we feel physically
- (2) How we feel emotionally
- (3) Our thoughts
- (4) Our behaviour
The Sleep Cycle
Sleep occurs in cycles each lasting about 90-110 minutes. We have 4- 6 of these cycles in a night’s sleep.
Prior to the beginning of sleep the brain produces Beta waves.
This is when we are awake. The brain then starts to slow as we move into the next stage.
NREM Sleep – Stage 1 (5 -10 minutes)
Bridge between awake and asleep – the brain starts to produce Alpha waves and starts to slow down. During this stage you can suddenly feel a body jerk and also can feel as if you are falling. (Lasts only a couple of minutes)
NREM Sleep – Stage 2 (around 20 minutes)
Theta waves (restful and reparative to immune system). Breathing slows and the person may twitch. They drift in and out of sleep and can be easily awakened.
Breathing and heart rate slow further, body temperature cools and you become less aware of the outside world. Theta waves continue with bursts of brain activity called spindles. This makes up 45 -50% of adult sleep.
Both stage 1 & 2 are still light sleep and if wakened people will often claim they have not been asleep at all. This can cause misinterpretation of time asleep.
NON – REM Sleep stages 3 & 4 (recently combined as one stage)
This is deep sleep with Delta waves. Sometimes called Delta sleep. Breathing and heart rate at their lowest level.
Muscle activity decreases
Brain consolidates what it has learned during the day.
If wakened up feel disorientated and groggy.
Sleep walking may occur at this point in sleep.
Breathing and blood pressure increase
Voluntary muscles become paralysed
Shallow stage of sleep
Makes up about 20% of total sleep. Each cycle extends a little throughout the night.
Begins 70-90 mins after falling asleep
Some theories believe unnecessary information from the day is trimmed and discarded by the brain
Good sleep includes time spent in each of the cycle stages and a significant amount of time in deep sleep.
Sleep problems can include difficulty getting to sleep, staying asleep or not gaining quality sleep in each stage of the cycle
How we sleep can also become a habit but this can be relearned.
Insomnia is difficulty sleeping. It is the most commonly reported mental health problem in UK. 40% of those in UK sleep less than 6 hours per night.
Acute < 1 month
Chronic is > 1 month and is related to activation of mind and body
Once we become concerned about sleep we become tense and produce adrenaline, have higher blood pressure and find it difficult to relax. Our body is in the fight flight state and we can start to feel frustrated and angry which makes it worse. Our worry that we won’t sleep then becomes a self-fulfilling prophecy.
The results of poor quality sleep
Low concentration High irritability
Low memory function High frustration
Low immune system High sleepiness
Note: fatigue is different to feeling sleepy. Fatigue is a lack of energy while wide awake and doesn’t make you want to sleep.
Sleep and Pain
Pain is also a psychobiological process. If we stub our toe we have acute pain. The message travels up our spinal cord through what we call the pain gate and is interpreted by our brain. The pain is felt in the brain not the toe. In a few minutes the pain will pass and we forget about it. We call this an acute pain. This does not tend to interrupt sleep.
When a pain goes on for a long time it takes on a different meaning to us. We begin to expect it, to look for it and dread it which in turn can cause low mood. We can feel helpless to stop what is hurting us. This is chronic pain and is made up of 2 elements
- The primary pain i.e. the physical source
- The secondary pain i.e. what we think about it
Sometimes the primary pain can go away but the secondary pain remains long afterwards because of our perception of it.
Experience of pain which becomes chronic reduces the quality of our sleep because
- (1)It feels uncomfortable physically and psychologically
- (2)Micro arousals (i.e. going into a lighter phase of sleep) tend to happen more frequently so we are not rested. Without chronic pain the person tends to simply move back into a deeper sleep phase.
- (3)We begin to give sleep a different meaning than we did before we were in pain. It becomes a bigger priority and the story we tell ourselves about sleep can add to our distress.
The good news is that once we start to think about making our quality of sleep better the research suggests we can usually find at least some way of improving things.
Quality and duration of sleep tend to increase.
What do we need to know?
Effects of Light
The master clock for the brain is made up of a group nerve cells found just above the optic nerve (SCN – Suprachiasmatic nucleus) and is controlled in the hypothalamus. 3 types of light sensor in the eye (rods, cones (colour), and a brightness detector). Signals pass from the eye to the brain about the amount of light in the environment. As the amount of light decreases the brain gets the signal to create more melatonin which makes us feel sleepy.
- Blue light stimulates the brain to produce less melatonin so we feel less sleepy (IT equipment, TV, phone etc all produce blue light)
- Non blackout curtains in summer allow light in so we wake earlier/ find it difficult to drift off to sleep.
- Brain produces more serotonin when there is more light. Serotonin is a neurotransmitter or chemical messenger in the brain. Its level is affected by our immune system so we need more sleep when we are ill and immunological diseases have an effect on our sleep.
Humans naturally sleep nights and wake during the daytime. There is a genetic element to whether you are a morning person or more prone to insomnia but within this you can still make adjustments. People regularly working shifts for example affect their natural pattern which causes increases in ill health.
Experience of psychological health issues can affect the sleep cycle. Poor sleep makes us less receptive to positive emotions and we are therefore more likely to feel miserable during the day.
Depression – REM sleep and the number of eye movements within that sleep is greater. The sleeper enters REM sleep earlier in the cycle. It is thought that increased dreaming may cause a vulnerability to increased Depression.
Both dreams and hallucinations involve deregulation of dopamine production. The level of dopamine affects pain perception, movement, memory, problem solving, attention and planning.
Anxiety – when anxious a sleeper spends less time in deep sleep. This is a refreshing part of sleep which consolidates the learning and memories of that day (Non REM).
The anxious mind finds it difficult to relax which causes increased arousal and adrenaline
We worry that we won’t sleep which becomes a self-fulfilling prophecy e.g. we clock watch and think about how much sleep we have missed
The clock takes on a new meaning and becomes a measure of our success or failure at sleeping. Its presence on the bedside table can become a constant critic of our sleep performance.
Great British Sleep Survey (2016) spoke to (N= 6708, 1/3 Men, 2/3 Women) people about their sleep experiences.
They reported insomnia affected; mood, energy, relationships, irritability, ability to stay awake during the day, ability to carry out tasks effectively.
Over sleeping began to occur among 15-40% of those who reported feeling depressed.
Hormonal changes resulting in increased likelihood of type 2 diabetes & obesity.
Decreased capacity to exercise which had a negative effect on mental wellbeing and therefore further contributed to insomnia.
Sleep Behaviours Can Become a Habit
e.g. Sleep Grazing
When we are tired it is tempting to sleep graze by taking little naps during the day.
The problem with this is that it:
- Further disrupts sleep pattern as don’t want to sleep at night
- Never reach deep sleep as it is brief
- Don’t recover sleep debt
- Don’t reach delta wave deep refreshing sleep
Physical health can restrict sleep from something as basic as a cold which stops you breathing due to a blocked nose.
e.g. Sleep Apnoea – snoring during REM sleep due to pauses in breathing. Caused by tissue at back of throat and base of tongue which obstructs airways. It is affected by the shape of the neck, alcohol, smoking and weight. More common in older men. Can be treated with positive airway pressure mask.
What Can We Do to help address this?
How to Improve Our Sleep
Good sleep hygiene can improve our sleep quality
Stays in the system a long time as it is hard for the body to break down
Stimulates the Central Nervous System
Causes increased heart rate
Causes adrenaline production
Suppresses melatonin a hormone which helps us feel sleepy
Makes us fall asleep more easily but the quality of sleep is not as good
Interrupts sleep pattern in the second half of the night
Diuretic so need to get up to the toilet
Is a depressant and causes low mood which reduces sleep
Going cold turkey after a lot of alcohol causes withdrawal symptoms
Difficult to sleep if hungry so light snack can help (not protein)
Rice/oats cause small melatonin production
Diary contain tryptophan which aid manufacture of melatonin in body
Makes us more active and less sleepy
Better earlier in the day as increases adrenaline
Older adults found to sleep better with aerobic exercise
Physical fitness increases metabolism which results in better sleep
Reduces anxiety and improves mood causing better sleep
No IT equipment or TV in bedroom
No alarm with permanent light on bedside
Reduce blue light exposure
Stop interaction on social media etc at least an hour before sleep
Low lighting on run down to sleep
Blackout when wish to sleep (Blackout curtains in summer)
Noise stopped – or earplugs can help
Temperature – not too hot (17 degrees)
Most common sleep medications are called hypnotics. Only helpful in short term (NICE guidelines say 2-4 weeks) as they are addictive also have rebound effects once come off them which can make sleep worse than it was to start with.
Aim to challenge the underlying thoughts and feelings about sleep.
Cognitive Behavioural Therapy (CBT) has been found to be an effective part in treatment of insomnia. Including this as treatment package as follows will maximise your chances of making a positive change;
- Sleep Hygiene (as above)
- Relaxation Training
- Adjusting sleep patterns
- Altering the thoughts and behaviour which hinder sleep
People with insomnia often find it difficult to relax naturally before they go to sleep
Useful to use
- Breathing – Finger breathing/breathing and visualisation
- Muscle tension
- 1 hour wind down
These all take practice before they are mastered and it may take a little while to start to feel it is a comfortable part of your routine.
Adjusting Sleep Patterns
Monitor sleep diary for 2 weeks to see what is actually happening
Review findings in light of sleep hygiene protocol
Altering the Thought and Behaviour Which Hinder Sleep
Make the bedroom the place to sleep not eat/work/watch TV. If you wake and don’t get back to sleep within a few minutes try a relaxation exercise. If still awake get up and do something relaxing like reading the paper in another room until feel sleepy then return to bed.
If you have a chronic pattern can use sleep restriction but with professional help.
Use of Thoughts monitoring (See Thoughts Diary)
- Espe C.A (2006) Overcoming Insomnia and Sleep Problems. A self help guide using Cognitive Behvaioural techniques. London: Constable and Robinson Ltd.
- Glovinsky, P. & Speilman, A. (2006) The Insomnia Answer. A personalised programme for identifying and overcoming 3 types of insomnia. Perigee Trade.
- Espie C.A. ( 2011) An introduction to coping with sleep problems. London, Constable & Robinson (Booklet)