JRSM >
Volume 96, Number 12 >
Pp. 577-581
University of Liverpool Medical School, Department of Primary Care, Harrison Hughes Building, Brownlow Hill, Liverpool L69 3GB, UK
E-mail: mlw{at}liv.ac.uk
 | INTRODUCTION |
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 TOP INTRODUCTION HOW IS DEPRESSION DIAGNOSED?HOW CAN DEPRESSION BE...THERAPEUTIC OPTIONS FOR...CONCLUSIONSREFERENCES |
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More than 40 years have passed since Hinton drew attention to the issue of mental distress in the dying6 yet surveys still point to much unrecognized suffering;7 as much as 80% of the psychological and psychiatric morbidity of patients with cancer goes unrecognized and untreated. One reason is that many patients choose not to disclose their symptoms—perhaps because they feel it is a waste of the professional's time or because they think they are in some way blameworthy.8 But another factor may be that medical and nursing staff lack confidence in diagnosing depression in these circumstances.9 In this article I review the methods that can help in detection of depression and the options for intervention when it is identified.
| HOW IS DEPRESSION DIAGNOSED? |
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TOPINTRODUCTIONHOW IS DEPRESSION DIAGNOSED?HOW CAN DEPRESSION BE...THERAPEUTIC OPTIONS FOR...CONCLUSIONSREFERENCES |
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In patients with advanced cancer, symptoms 6-8 are almost universal and there was much controversy over whether they should be included and, if so, their importance in the diagnosis of depression in such patients. Some workers reported that feelings of worthlessness, helplessness and hopelessness, feelings of excessive and inappropriate guilt and thoughts of self-harm were particularly discriminating;10,11 indeed, when somatic symptoms were omitted from the criteria, the point prevalence of major depression dropped from 42% to 24%.11 Discussing the complex matter of which symptoms are attributable to the cancer and which to depression, Endicott12 proposed modified criteria for depression in which alternatives were substituted for the somatic symptoms—for instance, instead of 'poor appetite', 'fearfulness or depressed appearance in body or face'. Endicott also stressed the importance of asking patients with cancer about suicidal ideation. When the research diagnostic criteria were compared with Endicott's criteria, it was found that small differences in the application of symptom severity thresholds could cause large differences in prevalence rates for depression.13 The inclusion of somatic symptoms only inflated the rates of diagnosis when these symptoms were used with a 'low threshold' approach.
Whilst some patients require expert psychiatric assessment, many can be adequately assessed by a doctor or nurse who has acquired the basic skills. Ideally there should be an integrated referral system that offers ready access to a mental health professional when needed. At present few hospices have psychiatric input of this sort.14
| HOW CAN DEPRESSION BE ASSESSED? |
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TOPINTRODUCTIONHOW IS DEPRESSION DIAGNOSED?HOW CAN DEPRESSION BE...THERAPEUTIC OPTIONS FOR...CONCLUSIONSREFERENCES |
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One method of assessing depression is to use rating scales. Below I discuss the most frequently used scales and why those used in clinical trials may be unsatisfactory in palliative care.
The Hospital Anxiety and Depression Scale
The Hospital Anxiety and Depression Scale (HAD) is a fourteen-item scale
devised in 1983 by Zigmond and Snaith for use with medical
patients.17 A main
characteristic is the exclusion of symptoms that may have both an emotional
and a physical aetiology—e.g. dizziness or sleep disturbance— and
it is a widely used depression rating tool in cancer and palliative care. The
depression scale is based on anhedonia—the complete loss of enjoyment or
'exclusion from the pleasure
dome'.18 The
authors of the scale stated that this symptom would indicate which patients
might respond to antidepressant
medication.19 The
General Health Questionnaire (GHQ), the Rotterdam Symptom Checklist (RSCL) and
the HAD scale together with the Psychiatric Assessment Schedule were assessed
by Ibbotson et
al.20 in a
prospective study of 513 patients with cancer. The HAD scale performed best in
patients who were disease-free or receiving treatment. Anhedonia, which is
measured by five of the seven items on the HAD depression subscale, is a very
common feature in patients and cannot be relied upon alone to differentiate
depressive illness from other mental
illness.21 Le
Fevre,22 comparing
the HAD and the GHQ, recommended summing of the scores on anxiety and
depression subscales rather than use of the depression subscale alone. A
combined cut-off score of 20 achieves a sensitivity of 0.77 and specificity of
0.85 and a positive predictive value of 0.48. A further
study23 in 100
patients receiving palliative care with an estimated prognosis of six months
or less showed that, when used as a screening tool, the depression and anxiety
scales of the HAD were of low efficacy when used singly. The optimum threshold
was at a combined cut-off of 19, which had a sensitivity of 0.68, a
specificity of 0.67 and a positive predictive value of 0.36
(Table 1).
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The Zung Self-rating Depression Scale
The Zung Self-rating
Scale24 is a
twenty-item self-report measure of the symptoms of depression in which
patients rate their symptoms according to how they have felt in the previous
week. Scores are categorized into four different levels reflecting the
presence or absence of depressive symptoms. As with other screening tools the
aim is not to make a diagnosis but to identify patients with clinical symptoms
suggestive of depressive illness. The Zung scale and the briefer eleven-item
Zung scale (which excludes nine items relating to somatic symptoms) has been
found useful in cancer patients, predominantly those with stable
disease.25,26
The Edinburgh Depression Scale
The Edinburgh scale was devised by Cox et
al.27,28
as a screening tool for postnatal depression. With its ten items selected to
exclude the somatic symptoms of depression, it was devised to be administered
by healthcare workers with no specialist knowledge of psychiatry. The original
scale was validated in 84 mothers in the postnatal period and found to have a
sensitivity of 0.86 and specificity of 0.78 (with cutoff threshold 12/13). The
authors believed it could be used for other populations and the questions
concerning guilt, helplessness/hopelessness, low mood and thoughts of
self-harm seemed particularly important diagnostic symptoms of depression in
the terminally ill. The Edinburgh Scale was therefore assessed against the
Present State Examination for depression according to International
Classification of Diseases (10th edition) criteria in 100 inpatients with
metastatic cancer who were receiving palliative care. In this study a cut-off
threshold of 13 gave optimum sensitivity 0.81 and specificity 0.79, with
positive predictive value 0.53 (Table
2).29
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Visual analogue scales and simple questions ('Are you
depressed?')
Answers to the simple question 'are you depressed?' can be
informative.30,31
Chochinov in the USA assessed 197 palliative care inpatients using four
screening tools together with a diagnostic interview for depression according
to Research Diagnostic Criteria. The diagnostic interview was adapted from the
Schedule for Affective Disorders and Schizophrenia (SADS). The question
'are you depressed?' (taken from the full SADS interview) correctly
identified the eventual diagnostic outcome of every patient (sensitivity,
specificity and positive predictive value all 1.0). Addition of a second
question about loss of interest reduced the specificity (0.98) and positive
predictive value (0.86) though not the sensitivity. Work in the UK has yielded
less favourable
results.32 When
assessed against a clinical psychiatric interview, the question 'are you
depressed?' had sensitivity and specificity less than 0.6. A possible
reason is that, in the original study, the question was included also in the
validating interview; moreover, the responses will depend greatly on
interviewers' and patients' understanding of the concept of
depression.
Thoughts of self-harm
Although by no means diagnostic, thoughts of self-harm are important
indicators of depression in the terminally ill patient. In any form of
psychiatric interview or screening in such patients they should be inquired
about. An overwhelming feeling of helplessness and hopelessness is an
indicator of suicidal
risk33 and such
feelings are commonly reported also by patients who are depressed. Brown
et al.34
and Chochinov et
al.35 found
that, among terminally ill patients, suicidal thoughts and desire for death
were almost entirely confined to patients with a psychiatric disorder. Tiernan
et al.36
examined the question by exploring the relations between desire for early
death, depressive symptoms and antidepressant prescribing in 142 patients.
They used the HAD scale and four additional questions—'I go to sleep
hoping that I won't wake up'; 'I think of ending my life but I would not
do it'; 'I would end my life if I had a chance'; and 'I
wish that doctors would do something to end my life'. 120 patients stated they
had never desired an early death and only 2 patients had a strong wish for
death. Depressive symptoms were frequently identified by the HAD scale, but
the components of the HAD scale may mean that the true levels of depression
were
underestimated.23
The desire for early death correlated strongly with the depression
scores—as found also by others. Tiernan found that only 12% of patients
were receiving antidepressant medication and judged that antidepressants were
underutilized in this
population.38
What of actual suicide in patients with cancer? Farebarrow,39 reporting on 16 severely incapacitated patients who committed suicide, concluded that intention rather than physical strength is the important variable. Advanced physical disability was also present in more than two-thirds of the 88 cancer suicides studied by Bolund.40,41 35 of these patients had developed a mental illness after the cancer was diagnosed, the most frequent conditions being depression and what Bolund terms a 'reaction to illness' (presumably an adjustment reaction).
| THERAPEUTIC OPTIONS FOR DEPRESSION |
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TOPINTRODUCTIONHOW IS DEPRESSION DIAGNOSED?HOW CAN DEPRESSION BE...THERAPEUTIC OPTIONS FOR...CONCLUSIONSREFERENCES |
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Psychotherapy is designed to achieve lasting change and in the psychiatric setting is often used for patients with deep-seated psychopathology. Spiegel43 identified four basic components of psychotherapy when used in patients with cancer—namely, social support, especially when group psychotherapy is used; emotional expression; cognitive restructuring; and coping skills training. There are indications that cancer patients who become depressed have a distinct pattern of coping skills.44
Adjuvant psychological therapy has been found beneficial in patients with cancer. The theoretical framework is founded on a premise that cancer-related psychological distress stems from the personal meaning of the disease to the patient and the patient's own coping skills.45 Patients are seen for six one-hour sessions, the main aims being to induce a fighting spirit, to encourage expression of emotions, to challenge negative behaviour and to look at cognitive techniques for countering negative behaviour. In a further study46 this strategy outperformed counselling in terms of sustained fighting spirit, coping with cancer, anxiety and self-defined problems. This latter study included patients at various stages of cancer including advanced metastatic disease. Clearly psychological support is important for all patients with cancer, and the relative merits of counselling and focused psychotherapy are still debated. In practice, the choice is limited by the extreme shortage of psychologists in the UK; indeed, the popularity of counselling within cancer and palliative care services may reflect the ease of access to counsellors rather than evidence that counselling is of major benefit. A study in primary care has suggested that, although counselling can be of value in depression,47 antidepressants act faster and therefore may be more appropriate for patients with short life expectancy.
Psychotropic medication
In patients with cancer the principles of treatment with antidepressant
medication are the same as in any other
patient.48 The
underprescribing of antidepressants probably stems from
misconceptions—for example, the notions that medication is pointless
when patients have an obvious reason for being depressed, that psychological
treatments are better or that drug treatment is incompatible with
psychological treatment.
A patient with cancer starting on an antidepressant has a probability of responding similar to that of depressed patients in the general population. In a study of 156 patients with cancer referred to a liaison psychiatry service49 antidepressants were prescribed to two-thirds of the patients and 80% showed a good clinical response with few side-effects. Tricyclic antidepressants are frequently used in palliative care for the treatment of neuropathic pain, but the doses for this purpose are much lower than those required for an antidepressant effect. With full dosage their anticholinergic side-effects are commonly troublesome in palliative care patients treated for depression. There is less evidence for the use of selective serotonin reuptake inhibitors in treatment of neuropathic pain, though sertraline and paroxetine have been reported to relieve the pain of diabetic neuropathy.50,51 The selective serotonin reuptake inhibitors lack the anticholinergic cardiac and sedative effects of the tricyclic drugs and are safer in overdose but may cause nausea, diarrhoea, anxiety and insomnia. Few studies have been done in depressed patients with advanced cancer.52 All antidepressants take about three weeks to work but side-effects tend to begin in the first few days and hamper adherence to treatment. One of the newer antidepressants mirtazapine seems clinically to have a good side-effect profile when used for patients with advanced cancer.53 The choice of antidepressant is therefore governed by a decision on which drug is best suited to the individual patient. In a large community study selective serotonin reuptake inhibitors were better tolerated and more likely to be continued than tricyclic antidepressants.54
Psychostimulants
Psychostimulants such as dexamphetamine increase the sense of well-being
and improve mood. They work by promoting the release of biogenic amines and
must be taken early in the day to avoid insomnia. The dose is normally
maintained for seven to ten days and is then slowly reduced. They are
generally safe, but care needs to be taken in patients with multiple organ
failure. Psychostimulants are used frequently in the United
States55,56
but seldom in the UK or continental
Europe.57
| CONCLUSIONS |
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TOPINTRODUCTIONHOW IS DEPRESSION DIAGNOSED?HOW CAN DEPRESSION BE...THERAPEUTIC OPTIONS FOR...CONCLUSIONSREFERENCES |
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Screening tools have a role, if used judiciously. Assessment of depression requires sensitive questioning about the patient's perception of his or her mood together with inquiry on areas such as guilt, hopelessness, helplessness and suicidal thoughts.
| REFERENCES |
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TOPINTRODUCTIONHOW IS DEPRESSION DIAGNOSED?HOW CAN DEPRESSION BE...THERAPEUTIC OPTIONS FOR...CONCLUSIONSREFERENCES |
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