Sleep is universal and is a requirement that cannot be resisted. We spend a third of our lives sleeping. It is believed that sleep touches every aspect of our physiology and psychology and daily functioning. Sleep is needed for restoration, conservation of energy and memory consolidation. Sleep is essential for all animals. While asleep there is reduced awareness and reduced responsiveness to the outside world of our mind. There is also reduced muscle activity and to the observing person an asleep individual is relatively inactive. Sleep is actively initiated by the brain and is tightly controlled by complex neuronal activity.
Normal sleep consists of several stages or cycles of sleep. After falling asleep the brain quickly goes into stage 1 (drowsiness) and followed by the intermediate stage 2 and then deep sleep or stage 3. These are stages of Non-REM sleep. The other sleep stage is REM sleep and this is characterised by rapid eye movements and the muscles go into relaxation and the person is unable to move. In this stage the person is most likely to dream, the heart rate increases, and breathing can become erratic. The brain will go through several cycles often lasting 60 to 90 minutes. The first half of the night is spent mostly in deep sleep and the latter part of the night in REM sleep. The amount of sleep changes with age. Infants enter sleep through REM sleep and comprises about 50% of total sleep. As the person gets older deep sleep becomes more important and the total sleep duration reduces. Most adults require around 8 hours of sleep. Older people often take much longer to fall asleep. Stage 3 or deep sleep is the sleep that is the most difficult to wake from and is also the most restorative sleep. Deep sleep makes up about 20% of sleep time and stage 2 accounts for 50% of total sleep time (in adults).
Sleep is closely regulated and there are 2 processes that are important. The first is the Homeostatic Process. Homeostasis means the tendency of a system, especially the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function. The propensity to sleep builds during the waking period and is dissipated during sleep. So, the longer a person is awake the more a feeling of sleepiness builds and the longer a person has been asleep the lower the sleepiness immediately after. It is not possible to store sleep by sleeping in advance and also missing sleep can only be partially corrected.
The second process is the Circadian Rhythm. Light is the driving factor. Wake promoting signals from light entering the eyes via the specialized retinal cells. These signal the pineal gland to inhibit melatonin production. Blue light has the most potent effect. During darkness, the reduced light signal helps to promote sleep due to the increased production of melatonin. Light is the “time giver” to regulate the body clock. Other external signals include social activities, exercise and eating habits. The body clock includes, in addition to the sleep wake cycle, the rhythm of core body temperature, secretion of hormones like cortisol and growth hormone as well as many other physiological processes.
There are many different types of sleep disorder. The American Academy of Sleep Medicine recognises 6 different groups of disorders:
- Breathing related sleep disorders
- Obstructive sleep apnoea
- Hypersomnolence disorder
- Sleep walking, night terrors (stage 2 and 3) and nightmares (REM sleep disorder)
- Circadian rhythm sleep-wake disorders
- Delayed sleep phase type
- Insomnia disorder
- Difficulty initiating, maintaining sleep or early morning wakening
Anchor Psychiatry Group, in partnership with Marilyn Sher, Consultant Clinical and Forensic Psychologist, offer assessment and treatment of insomnia, parasomnias and circadian rhythm sleep-wake disorders and well as sleep problems related to mental health conditions, like depression, or physical health conditions, like pain or when sleep problems are due to medication. The treatment of insomnia includes a combination of medication and Cognitive Behavioural Therapy for Insomnia.
Who is the clinic for and what to expect
If you believe that you have a sleep problem that has been causing distress for several months than you may have a serious sleep disorder. Your GP can refer you for a comprehensive sleep assessment and treatment. After we have received the referral you will be send a detailed questionnaire for background information. If you have a smartwatch or similar device it is very helpful to wear it for a period of time before the appointment and bring the results with you. Smart watches or similar devices are very helpful in the identification of circadian rhythm disorders and can give an accurate measure of the total sleep time. You will then be offered an initial appointment with our psychologist who will take a detailed sleep history and will ask you to keep a sleep diary for a minimum of 1 or 2 weeks minimum. Following this you will see one of the Anchor Psychiatry Group psychiatrists (a doctor with specialist training in mental health) who will take a further history to make a diagnosis and agree a treatment plan with you. After that you will be given a further 5 sessions with the psychologist to go through a comprehensive treatment called CBT-I (cognitive behaviour therapy for insomnia).
The sleep clinic is not able to offer diagnosis and treatment for other sleep disorders like narcolepsy and obstructive sleep apnoea, because these need to be investigated by a specialised sleep clinic that can complete detailed sleep assessments. The nearest clinic to Norfolk is at Addenbrookes Hospital Cambridge. If we believe that your sleep problems are due to narcolepsy or obstructive sleep apnoea, we can make recommendations for your GP to refer you to the specialist sleep clinic. In these cases CBT-I can still be very valuable, because it helps to maintain a healthy sleep cycle.