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Depression and sleep disturbance

Tony Gillam
BA(Hons) RMN DipCPN
Mental Health Nurse
Clinical Manager of Worcestershire's Early Intervention Team

Depression can have a devastating effect on individuals and their families, as well as having a major impact on society. According to the World Health Organization depression is the fourth leading cause of burden of disease and disability worldwide.(1) Just like common physical illnesses depression can have very serious consequences if not properly and effectively managed.
About 5% of the population are clinically depressed but it is estimated that as many as one person in three may experience an episode of depression during the course of their lives. Of those patients consulting their GP, about 5% will be suffering from major depression; another 5% will have milder symptoms while a further 10% will be showing some level of distress.(2) The majority of depressive episodes (over 90%) are managed in primary care.(3)

Symptoms of depression
Depressive illness can range from mild, through moderate, to severe depression. Depressed mood is usually the central feature but there are a range of other symptoms which are common in depression. These include a loss of enjoyment, interest and energy, disturbed (usually decreased) appetite, sleep and libido; agitation or slowing of movement; poor concentration and mental slowing; negative thinking or hopelessness; feelings of guilt or worthlessness; and thoughts of death or suicide.(4)
The symptoms of depression can be categorised into the three domains of mood/motivation, psychological symptoms and physical/biological symptoms (see Table 1). Clearly, there is considerable overlap between these domains. All of these symptoms can impact on social functioning, leading to difficulties in carrying out routine activities or performing at work, difficulties with home life and withdrawal from friends or social activities.(5)

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Causes
The causes of depression are complex and no single cause has been found, nor does any single model provide a satisfactory explanation for the condition. Like other mental health problems, depression is not a purely biophysical illness and it is therefore important to consider the social and psychological aspects alongside the biological. For the purposes of this article, however, we shall focus on one of the major biological symptoms of depression - sleep disturbance.

Sleep
The Elizabethan dramatist and pamphleteer Thomas Dekker famously described sleep as "the golden chain that ties health and our bodies together".(6) It is generally accepted that we need sleep to maintain physical and mental health. Sleep can be defined as the regular period in every 24 hours when we are unconscious and unaware of our surroundings.(7) Most adults need around seven to eight hours sleep each night.
There are two main types of sleep: rapid eye movement (REM) sleep and non-REM sleep. REM sleep is so called because, during this phase, the eyes move rapidly from side to side. REM sleep comes and goes throughout the night and constitutes about one fifth of sleep time. During REM sleep the brain is very active and the muscles very relaxed and it is during this phase that dreams occur. By contrast, during non-REM sleep, the brain is quiet but the body may be restless. Hormones are released during non-REM sleep and the body repairs itself.  

Problems with sleep
Occasional lack of sleep has no adverse health consequences but, after several sleepless nights, people will experience:

  • Feeling tired all the time.
  • Dropping off during the day.
  • Difficulties with concentration.
  • Impaired decision-making.
  • Starting to feel depressed.

It is clear that there is some overlap between the psychological and biological effects of repeated lack of sleep and the symptoms of depression. Tiredness, poor concentration and a lowering of mood are common to both.
Typically, patients with depression will experience early morning wakening where (although they may initially be able to get to sleep) they wake in the early hours and are unable to resume sleep. Difficulty getting to sleep (onset insomnia) is more often associated with anxiety rather than depression although, of course, it is not uncommon for people with depression to also have anxiety problems.
It is known that antidepressants have an effect on sleep patterns, both in healthy volunteers and in depressed patients.(8) The relationship between the biological aspects of depression and the biological effects of antidepressants on sleep is a complex one so it is helpful, first, to understand more about depression and antidepressants.
 
Biological aspects of depression
There are various hypotheses for a biological cause for depression, with many lines of evidence pointing to the involvement of brain amines in the depressive process. The evidence is strongest for a malfunctioning of the neurotransmitter serotonin, although it is unclear whether low levels of serotonin are a primary cause of depression or secondary to some other abnormality.(9) Nevertheless, this hypothesis led to the development of antidepressant drugs which act to increase levels of serotonin (see below).

Treatment of depression
In April 2007 the National Institute for Health and Clinical Excellence (NICE) issued its amended guideline on the management of depression in primary and secondary care.(10) As well as providing guidance on the safety of antidepressant drug treatments it also recommends effective psychological treatments for people with depression. The evidence shows that the majority of depressed patients will respond to antidepressant medication or to "talking treatments" or both.
Antidepressants are not generally effective in milder forms of acute depression. The evidence suggests that antidepressant medication should only be used in more severe major depression and, more surprisingly, in long-standing milder depressive disorders (eg, dysthymia).(11)
Particular indicators for the use of antidepressants are:

  • The presence of biological symptoms (see Table 1).
  • A tolerance of antidepressant use.
  • A previous good response to antidepressants.(12)

Types of antidepressant
There are three major classes of antidepressants, as well as a number of others that do not fit easily into classification (see Box 1). The monoamine oxidase inhibitors (MAOIs) tend not to be used as a firstline treatment because they may be less effective and have dangerous interactions with some foods and drugs.(13) The tricyclic drugs, like the MAOIs, were discovered in the 1950s, while newer antidepressants (like the selective serotonin-reuptake inhibitors [SSRIs]) were not introduced into the UK until the late 1980s.(14) There is no evidence that SSRIs are more effective than tricyclics but their side-effects are better tolerated. Sedation is generally less of a problem with SSRIs, which can be an important factor for patients who continue to drive or work. The other major consideration is safety in overdose. SSRIs are less cardiotoxic in overdosage and are therefore preferred where there is a significant risk of deliberate self-harm.(13)

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Effects of antidepressants on sleep
It has already been noted that antidepressants affect sleep patterns, with different medicines having different effects. SSRIs and MAOIs, for example, have the greatest effect on REM sleep. With SSRIs the decrease in REM sleep appears to be greatest early in treatment, but with MAOIs REM sleep may be absent for many months. SSRIs can disturb sleep early in treatment while trazodone, for example, promotes sleep. Most effective antidepressants improve sleep after a few weeks of treatment, but specific differences in the effects on sleep may influence the choice of antidepressant for particular patients. For example, mirtazapine (which improves sleep continuity) may be a good option for depressed patients with marked insomnia.(8)
While there are options for such patients, depression-associated sleep disorders remain a key challenge for healthcare professionals. Noncompliance with medication not only slows recovery, but also consequently fails to address poor sleep in the depressed patient, which may lead to a cycle of poorer sleep and worsening depression. The development of well-tolerated antidepressants that promote rather than inhibit sleep would be welcomed by patients with depression and mental health professionals treating them.

The role of the primary care nurse
The practice nurse has an important role to play in supporting patients with depression who have disturbed sleep. Well-informed practice nurses can educate, encourage and support patients in appropriate use of medication, and guide them towards other agencies that can help. These might include other professionals like community psychiatric nurses (CPNs), social workers, psychologists and psychiatrists, and also daycare or support groups. It will be clear from this article that recognising depressive illness is not always straightforward, and if a practice nurse suspects a patient may be depressed, this should be taken seriously.
Many patients value the opportunity to talk in confidence to somebody who they feel they can trust and who is nonjudgmental. The primary care nurse needs to check if the patient has been assessed by a professional skilled in the assessment and treatment of depression and to share her concerns about the patient with the GP. In some cases the patient may already be seeing a mental health worker. The practice nurse should liaise with others involved and consider her role in supporting the therapeutic process.
A major problem is compliance with medication. Patients may be dismissive of their own need for treatment, or may feel hopeless about the prospects of getting better. They may also be experiencing troublesome side-effects. The practice nurse can help by reassuring patients that depression is an illness and, like other illnesses, can often be improved with medication. Most people with depression get better. All medication has side-effects, and it is often a case of finding the medication which suits the person's symptoms best.
There are a few important points about antidepressants that practice nurses can reinforce with depressed patients:

  • Antidepressants are not addictive. Although sudden discontinuation has been identified as a problem, this can be managed by gradual tapering over a few weeks.
  • Patients need to give their treatment a reasonable length of time to work (at least four weeks).
  • Patients should continue treatment for up to six months after recovery, in order to prevent a relapse.(12)

As far as sleep is concerned, as we have noted, if this is a symptom of depressive illness then it will usually resolve in response to the treatment of the depression. The practice nurse can reassure the patient of this, but also give support in terms of "sleep hygiene" - those behaviours that promote continuous and effective sleep (see Box 2).

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Conclusion
Sleep disturbance is a common - one might almost say classic - symptom of depression. Sleep is essential to mental and physical health and wellbeing, and continued lack of sleep may be a contributory factor to, as well as an effect of, depressive illness. While sleep disturbance will usually resolve itself with effective treatment of depression, antidepressant noncompliance remains a limiting factor in terms of patient outcome, including sleep disturbance. The practice nurse can play an invaluable role by instilling hope of recovery, by helping the patient to understand the importance of sleep hygiene and by encouraging compliance with effective treatment.

References

  1. World Health Organization. The World Health report: making a difference. Geneva: WHO; 1999.
  2. Paykel ES, Priest RG. Recognition and management of depression in general practice:  Consensus statement. BMJ 1992;305:1198-202.
  3. Royal College of General Practitioners. Shared care of patients with mental health problems. Occasional paper no. 60. London: RCGP; 1993.
  4. Oyebode JR. Shared assessment, intervention and care for people with depression. In Nolan P, Badger F, editors. Promoting collaboration in primary mental health care. Cheltenham: Nelson Thornes; 2002.
  5. World Health Organization. Collaborating Centre for Research and Training for Mental Health (editors). WHO guide to mental health in primary  care. London: Royal Society of Medicine Press; 2000.
  6. Dekker T. The Guls Horn-booke. 1609. Available from http://darkwing.uoregon.edu/~rbear/dekker2.html
  7. Royal College of Psychiatrists. Sleeping well. London: RCPsych; 2005.
  8. Wilson S, Argyropoulos S. Antidepressants and sleep: a qualitative review of the literature. Drugs 2005;65:927-47.
  9. Bond AJ, Lader MH.  Understanding drug treatment in mental health care. Chichester: Wiley; 1996.
  10. National Institute for Health and Clinical Excellence. Depression: management of depression in primary and secondary care. Clinical guideline 23 (amended). London; NICE: 2007.
  11. Anderson I. Antidepressant drug treatment in primary care:  when, what and how? J Primary Care Mental Health 2000;4;3-5.
  12. Blenkiron P. The management of depression in primary care: a summary of evidence-based guidelines. Psychiatric Care 1998;5:172-7.
  13. British Medical Association and the Royal Pharmaceutical Society of Great Britain. British national formulary. London, BMA/RPSGB; 2003.
  14. Levi MI. Basic notes in psychopharmacology. 2nd ed. Newbury: Petroc Press; 1998.