depression - background information
This handout gives background information about depression. The main messages are that depression is very common but unfortunately is often not recognised. Encouragingly once the diagnosis is made, there are many effective treatments available. The information is intended primarily for depression sufferers and their families. At times it is somewhat concentrated and technical, so don’t feel you have to take it all in at once. Note points that seem relevant to you. You can then discuss them with your doctor or therapist. General health professionals may also find the handout of interest. The main points covered are:
ü what is depression?
ü how common is it?
ü what causes depression?
ü how long does it go on for?
ü what is depression?
The word depression is used to cover a whole spectrum of states from brief everyday feelings of unhappiness to profoundly disabling and life-threatening medical disorders. When a health professional talks about depression, the following nine symptoms1 are considered particularly relevant:
1.) depressed mood most of the day, nearly every day (as indicated by subjective report or observation by others) – in children and adolescents can be irritable mood.
2.) markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by subjective account or by others).
3.) significant weight loss when not dieting or weight gain (e.g. a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day.
4.) insomnia or hypersomnia nearly every day.
5.) psychomotor agitation or retardation nearly every day (observable by others).
6.) fatigue or loss of energy nearly every day.
7.) feelings of worthlessness or excessive or inappropriate guilt nearly every day (not just self-reproach or guilt about being sick).
8.) diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others).
9.) recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without specific plan, or a suicide attempt or a specific plan for committing suicide.
To be diagnosed as suffering from a major depressive episode, one would need to have suffered from five or more of these symptoms – including (1.) and/or (2.) – over the same two week period. Symptoms that are clearly due to a general medical condition should not be counted. A companion handout “Diagnosing depression” gives more detail about specific diagnoses such as major and minor depression, dysthymia, recurrent brief depression, manic/bipolar depression, and seasonal affective disorder. Clarifying the diagnosis is important in deciding what form of treatment is likely to be most effective.
Obviously just about everyone feels a bit low and depressed occasionally. This is part of the ups and downs of everyday life. If however you suffer persistently or recurrently even from only one or two of the nine symptoms, then this is a message it is likely to be worth doing something about. Mild subsyndromal depressions are associated with increased unhappiness, health complaints, social dysfunction and work disability2. They also signal considerably greater risk of developing more serious psychological disorders in the future3. It is better to put out fires while small rather than wait till they are blazing.
[cont.]
ü how common is it?
About I in 5 of us will experience a major depressive episode at some stage in our lives4. In fact about 1 in 20 of us is suffering from a major depressive episode right now. Recurrent brief depression (RBD) – as severe as major depression, but the individual episodes are shorter & more frequent – has a lifetime prevalence of about 1 in 65. Similarly dysthymia – low grade depression going on for years – affects about 1 in 15 of us at some point4. Obviously these syndromes overlap and we may suffer from different types of depression at different stages in our lives. Staying with the formal diagnoses of dysthymia, minor depression, RBD and major depression, more than 1 in 3 of the population will suffer from one or more of these disorders during their lifetime6.
Worryingly people are developing their first major depressive episode at progressively younger ages7. This does not just seem to be due to a greater willingness to report symptoms, as suicides and hospitalisations are also increasing in the young8. In fact research on current major depression by decade of age found the highest rate in the youngest age group studied9. Women especially have an enormous liability to depression onset in the second half of their teens. A further survey10 found that 50% of those with a history of major depressive episode had first onset by age 25. Traditionally depression has affected women much more than men, but this is changing. For example in 1980 the male admission rate to Scottish hospitals for depression was only half the female rate. By 1995 this ratio had increased to two thirds11.
ü what causes depression?
Just as panic disorder is based on inappropriate firing of primitive alarm fight or flight responses, so depression can be viewed as a distorted form of what was an evolutionarily adaptive withdrawal & re-evaluation response12,13. Emotions are crucially important in helping us to decide what to do. Clearly there are repeated times during our lives when goals or intentions we had turn out to be unattainable or outdated. For survival, humans need mechanisms that help them disengage from such situations. Feelings of frustration, unhappiness and even despair may well be telling us that our progress towards desired goals seems too slow or is blocked entirely14. This can usefully trigger a biologically programmed retreat-review-redirect reaction. Unfortunately there are times when our hopes have been dashed, but we also feel unable to let go and move on. This blocked disengagement reaction can form the basis of depression.
This way of understanding depression however is just one aspect of a more complex overall model that needs to integrate factors such as life events & difficulties, coping behaviour, cognitive style, interpersonal factors, genetics and childhood experience. It is often helpful to distinguish vulnerability factors, triggering factors and maintaining factors. See the companion handout “Why do we get depressed?” for an illustration of this. Upbringing and heredity contribute to an individual’s coping style, life situation and overall vulnerability to depression. Traumatic events and other types of trigger may then act to precipitate a depressed mood. How we respond to this experience – our behaviours, biology, thoughts and relationships – contribute towards maintaining or recovering from this depressed state.
It is important to remember as well that depressive symptoms can be caused or worsened by other illnesses and difficulties. Examples include underactive thyroid, anaemia, medical disabilities and alcoholism. There are often also additional psychological problems4 such as panic attacks, obsessive compulsive symptoms, eating disorders, and dysfunctional coping styles.
ü how long does depression go on for?
The issues of duration and recurrence of depression are very important. Nearly all episodes of depression do eventually get better15. Frequently though depression tends to recur. [cont.]
As stated on the first page of this handout, even quite mild symptoms of depression are well worth tackling. However we should focus particular treatment efforts on depressions that are severe or not getting better quickly enough or that have a high likelihood of recurrence.
Research in hospital outpatient departments shows that approximately 40% of people treated for major depression will recover within 3 months, about 60% within 6 months, and about 80% within a year15. Those with major depression who are treated by non-specialist health care professionals may do considerably less well16,17 with possibly only 20% fully recovered at 8 months18,19. Happily specialist care seems less important for more minor depressions16. Despite a slowing of recovery rate with increased episode severity20 and duration, virtually all major depressive episodes do eventually remit15. Clearly by definition recovery rates are rather different for other types of depression like dysthymia and RBD. Interestingly if someone gets a series of recurrent major depressive episodes, all of them tend to last similar lengths of time – unless of course one catches subsequent attacks and treats them more quickly. Overall these findings on recovery rate are fairly encouraging. Less welcome are the research studies on relapse and recurrence.
Typically relapse is defined as a return of major depression following incomplete recovery or after recovery that lasted less than six months21. Recurrence usually describes new episodes of major depression occurring after at least six months of recovery. Unfortunately the majority of those seen at hospital outpatient departments for major depression will experience at least one recurrence. This risk decreases the longer one stays recovered. One major research study22 found that 40% of outpatient recoveries relapsed by 1 year, 54% by 2 years and 76% by 5 years. Further research23 on those with more severe depression suggests they will experience an average of 5 or 6 depressive episodes in their lifetime and may spend as much as 20% of their time in a depressed state24. One of the strongest predictors of relapse is the number of previous episodes25. Also at high risk of relapse are those with “double depression”22 – a major depressive episode superimposed on pre-existing dysthymia (both these risk factors should become evident on discussion). Care should be taken too to monitor for persisting residual symptoms after recovery (see the list of symptoms on page 1, and check the BDI score). As many as a third of those with major depression may only make a partial recovery26 and this increases the risk of relapse. As one might predict from the earlier section on “What causes depression?”, genetic factors27 (evident from the family history), difficult early childhood experiences28,29(see the Traumatic events checklist and the PBI), social adversity30(see the Checklist of potential problem areas), coping & personality difficulties31(discuss Problem solving), quality of support in close relationships4,32(see the Degree of partner criticism scale, the Dyadic adjustment scale and the IBM), and poor social adjustment33 (see the Social adjustment scale) all also suggest more care should be taken subsequently to monitor for familiar early symptoms that warn depression may be returning. Early recognition and prompt treatment are very helpful34.
references:
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3. Horwath E, Johnson J, Klerman GL, Weissman MM. Depressive symptoms as relative and attributable risk factors for first-onset major depression. Arch Gen Psychiatry 1992;49:817-23.
4. Blazer DG, Kessler RC, McGonagle KA, Swartz MS. The prevalence and distribution of major depression in a national community sample: the National Comorbidity Survey. Am J Psychiatry 1994;151:979-86.
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7. Cross National Collaborative Group. The changing rate of major depression: cross-national comparisons. JAMA 1992;268:3098-105. [cont.]
8. Klerman GL, Weissman MM. Increasing rates of depression. JAMA 1989;261:2229-35.
9. Burke KC, Burke JD, Regier DA, Rae DS. Comparing age at onset of major depression and other psychiatric disorders by birth cohorts in five US community populations. Arch Gen Psychiatry 1991;48:789-95.
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16. Katon W, Robinson P, Von Korff M, Lin E, Bush T, et al. A multifaceted intervention to improve treatment of depression in primary care. Arch Gen Psychiatry 1996;53:924-32.
17. Friedli K, King MB, Lloyd M, Horder J. Randomised controlled assessment of non-directive psychotherapy versus routine general-practitioner care. Lancet 1997;350:1662-5.
18. Schulberg HC, Block MR, Madonia MJ, Scott CP, Rodriguez E, et al. Treating major depression in primary care practice. Eight-month clinical outcomes. Arch Gen Psychiatry 1996;53:913-9.
19. Schulberg HC, Block MR, Madonia MJ, Scott CP, Lave J, et al. The ‘usual care’ of major depression in primary care. Arch Fam Med 1997;6:334-9.
20. Ramana R, Paykel ES, Cooper Z, Hayhurst H, Saxty M, et al. Remission and relapse in major depression: a two-year prospective follow-up study. Psychol Med 1995;25:1161-70.
21. Frank E, Prien RF, Jarrett RB, Keller MB, Kupfer DJ, et al. Conceptualization and rationale for consensus definitions of terms in major depressive disorder: remission, recovery, relapse, and recurrence. Arch Gen Psychiatry 1991;48:851-55.
22. Keller MB. Diagnostic issues and clinical course of unipolar illness. In: Frances AJ, Hales RE, editors. Review of psychiatry. Vol 7. Washington, DC: American Psychiatric Press; 1988. p 188-212.
23. Angst J, Baastrup PC, Grof P, Hippius H, Poeldinger W, et al. The course of monopolar depression and bipolar psychoses. Psychiatrie, Neurologie et Neurochirurgie 1973;76:246-54.
24. Angst J. A prospective study on the course of affective disorders. NIMH Consensus Development Conference; 1984, April; Washington, DC.
25. Belsher G, Costello CG. Relapse after recovery from unipolar depression: a critical review. Psychological Bulletin 1988;104:84-96.
26. Cornwall PL, Scott J. Partial remission in depressive disorders. Acta Psychiatr Scand 1997;95:265-71.