We all take sleep for granted until we have problems with it and then we quickly remember how desirable a good night’s sleep is. All human abilities (like paying attention, memory recall and learning) are made worse by poor sleep and there is a close relationship between sleep and many psychological conditions such as depression and anxiety.
You can gauge if you are getting too much or too little by how you feel when you wake up. The familiar feeling of physical tiredness from being very busy or working hard is quite different to the mental exhaustion you feel when you wake after a bad night. A useful fact to know about waking up is that a few minutes after we physically get out of bed and start moving around, a burst of cortisol (a stress hormone) is released in the brain. This release of cortisol motivates you to get some food to eat and thereby replenish your body’s glucose supplies. So if you’re lying in bed feeling miserable and tired and need to sleep more, try getting up, walking around, making a cup of tea and a slice of toast and then see if you feel you need more sleep.
(I have a separate page which gives advice on how to get a good night’s sleep – go straight to it if you are looking for some top tips (known as “sleep hygiene”- click here)
Why do we need it?
It can seem surprising that human beings, who can be so full of life, energy, plans and activities, can, at a certain point each day, disengage from life, lie down and apparently become oblivious to the outside world for up to eight hours. (We spend up to one-third of our life asleep.) When we sleep we are vulnerable to attack since we are no longer aware of what is going on and are in no position to defend ourselves. Yet all mammals, birds and even cold-blooded reptiles sleep so there must be good reasons for it – although we are still at the early stages of understanding them.
Research has shown that there are two very distinct types: REM (rapid eye movement sleep when we dream) and non-REM sleep, also called slow wave sleep (SWS). Slow wave sleep is the dynamic, constructive time of physical healing and growth for animal organisms, a recuperative stage where the mind/body system rebuilds itself after a hard day surviving in the world. Substances ingested during the awake period are synthesised into the complex proteins of living tissue; growth hormones are secreted to assist with the healing of muscles and repairing general wear and tear in tissues; the immune system is boosted.
By contrast, in REM sleep large amounts of the brain’s energy reserves are expending on dreaming. Dreaming is clearly performing a very important function. Brain wave patterns measured by an electro-encephalogram (EEG) during sleep are similar to waking brain wave patterns. REM sleep occupies about twenty-five percent of a healthy adult’s sleep time and dreaming in this state is the deepest trance state known.
Who is more likely to suffer from insomnia?
Insomnia is defined as sleeplessness that occurs at least three nights a week for at least three months. It can occur at any time, but some of us are more prone to it than others. Women are twice as likely to get insomnia as men, shift workers and frequent international travellers are all more prone to bouts of sleeplessness, as are those of us who are worriers or over-thinkers.
It is important to know that poor sleep may be a side effect of medication or be related to a physical condition. We also tend to have more difficulties with sleep as we age and the hot flushes of menopause can cause severe sleep disruption. In elderly people, REM sleep (see below) decreases to about twenty per cent of sleep time and the time spent in deep sleep shortens. They often catnap during the day because they don’t get such good quality sleep during the night which can make their problem worse.
Sleep and physical illness
We sleep more when we are sick with an infection or develop a fever. When our temperature rises, our organs work more quickly, antibodies are synthesised more rapidly and antibiotics are taken up more quickly. It seems that the high temperature may kill off certain microbes. Even when we are asleep without a fever, our immune function works harder than when we are awake.
Excessive REM sleep and its knock-on effects may explain much of the suffering experienced by people with fibromyalgia where key symptoms are widespread musculoskeletal pain, a feeling of tiredness all the time and disturbed sleep often accompanied by vivid dreams. Consistent research has shown that FM sufferers have an excess of REM sleep and a deficiency of restorative sleep. In a Canadian experiment, acute fibromyalgia was able to be induced in healthy students who were woken up whenever they went into non-REM sleep, as indicated by brain wave readings but were allowed to continue REM sleep. After a few days they started to feel aches and pains and after a couple of weeks these pains had spread over their entire bodies. (Moldofsky et al 1975)
Sleep and Depression
In the 1960s it was discovered that depressed people dream more intensely and have longer periods of REM sleep, particularly in the early phases of sleep, than non-depressed people. Extended dreaming is exhausting, not just because it deprives us of restful and restorative slow-wave sleep (that should make up three-quarters of our sleep time), but also because it over stimulates the orientation response. This is the same expectation pathway in the brain that we need in the daytime to focus our attention on getting things done – it generates our motivation to do things and keeps us interested in life.
The sleep imbalance depressed people suffer from is why, despite sleeping for a long time after a stressful day, we can wake up still feeling tired and unmotivated. Exhaustion on waking and lack of motivation are features common to all depressed people and the reason is this: Depressed people dream more intensely and for longer periods because their brain is having to deal with an overload of arousals caused by excessive worrying. Our normal sense that life is meaningful comes from the actions we take but when our motivation levels are lowered because of over-dreaming, life can quickly come to seem meaningless. The natural delight we take in being alive and actively involved doing things drains away. For more information on depression, click here.
Sleep hygiene means habits that help you to have a good night’s sleep. Common sleeping problems are often caused by bad habits reinforced over years or even decades. You can dramatically improve your sleep quality by making a few minor adjustments to lifestyle and attitude. Go to my Sleep Hygiene page for some Top Tips to get Better Sleep!
Need some advice and support?
If you are struggling with getting a good night’s sleep or indeed any other emotional issues or life challenges and would like to talk things over in complete confidentiality, call Alison Winfield, Mindfully Well Counselling Cork on 087 9934541.Book a session today!
See also: Depression and sleep, Sleep well!