First published May 2006, updated May 2021

Two thirds of people admitted to a general hospital are over age 65 years, and up to two thirds of these will either have or will develop a mental disorder during their stay1. This means that an average general hospital will have around 200 older people with a mental health problem at any one time – significantly more than the local specialist mental health services. This figure will rise over the next 25 years as the population ages. The two most common mental disorders encountered in the general hospital are depression and dementia – which is why the National Service Framework (NSF) for Older People has focused on these conditions.

There are nearly 50 good quality studies on depression in older people in general hospital settings. Collectively, the studies find that the prevalence of depression in this patient group ranges from five to 58 per cent – with a mean of 29 per cent. This compares with the community mean of 12 per cent, and it implies that at any one time around 100 in-patients will have a depressive disorder of some degree2.

This prevalence figure is important – not only because it means an easily treatable condition is not being identified, but also because the outcome of other health interventions will be adversely affected by the patient having depression. A systematic review of the studies performed to date has shown that mortality, length of stay and rates of institutionalisation all increase with untreated depression2. These are all performance indicators in geriatric care – so the need to identify and treat depression would also seem important in terms of the management of general hospitals. Unfortunately, it has been reported that depression is rarely detected; although the detection rate has been cited at 26 per cent with a median of 10 per cent2.

Even when depression is detected, the use of treatment is very haphazard. Depression is as likely to be treated with benzodiazepines as antidepressants, and psychological therapies are almost unheard of. For example, less than a quarter of depressed people following hip fractures receive antidepressant treatment3. The simplest explanations for this is the treating physician’s lack of knowledge and skills, poor attitude and low confidence when faced with depression and other mental disorders.

Pitfalls in detecting depression in older people

Diagnosis

The main problem is in resolving issues of heterogeneity across the depressive syndromes. A reliance on diagnostic criteria for research means that major depression is the most often studied, while what is seen clinically is often not as severe – though patients do experience functional impairment and adverse medical outcomes comparable to those seen in major depression. Thus, subsyndromal major depression is important in geriatric medicine and needs similar treatment.

Attribution of symptoms

Depressive symptoms like low energy, insomnia and pain can occur in many elderly conditions, which means an underlying depressive disorder can be missed (i.e. it is attributed to the elderly condition). A more inclusive approach to symptoms would mean depression was always considered as a confounding factor. Also, explaining depressive symptoms in the context of a serious illness (e.g. someone would be expected to be depressed if they have a disabling neurological condition) may reduce the likelihood of a diagnosis of depression and subsequent treatment.

Differential diagnosis

Even if depression is diagnosed, there remains a possibility that it may be bipolar disorder rather than unipolar depression. There is little research on bipolar disorder in the elderly, but it is associated with organic aetiologies in around a sixth of cases. Multiple sclerosis, stroke and steroid usage are reported examples.

Bipolar depression is less likely to respond to an antidepressant if there is an organic aetiology – so identified cases of depression arising later in life that do not respond to treatment should be reviewed with this in mind. Delirium can present in a quiet withdrawn form that can be mistaken for a depressive disorder.

Why is depression detection important?

In a study at Duke University, conjoint trajectories of depression and physical illness outcomes in consecutively admitted elderly inpatients with minor depression and heart failure or pulmonary disease were followed to look at predictors of long-term outcome4 . Patients were placed into four depression-physical illness outcome trajectories: a) depression better, illness better; b) depression better, illness same; c) depression same, illness better; and d) depression same, illness same. By 12 weeks, 49.6 per cent had improved on both and 20.5 per cent on neither.

The admitting hospital, past psychiatric history, family psychiatric history, co-morbid physical illnesses, race and antidepressant drug treatment all independently predicted outcome trajectory. Improvement in depression and physical illness appeared to track closely together in these patients, and the baseline patient characteristics seem to predict which outcome trajectory was likely to occur after hospital discharge.

A Hungarian community survey of 11,122 persons aged over 35 years investigated the coincidence of depressive symptoms, vital exhaustion, cardiovascular disorders, stroke, and myocardial infarction5. In the survey, 20.3 per cent of the participants reported having experienced a cardiovascular disorder. Of these subjects, 52.1 per cent exhibited depressive symptoms (22.0 per cent minor depressive symptoms, 30.1 per cent moderate depression or worse), and 69.7 per cent exhibited vital exhaustion.

The frequency and severity of depressive symptoms did not differ significantly in patients who had suffered a myocardial infarction, stroke or neither; and the strength of relationships between these psychological variables and cardiovascular disorder does not appear to be different from the relationships demonstrated between both hypertension or diabetes and cardiovascular disorder. This suggests that the assessment and management of depressive symptoms and vital exhaustion should be routine procedures in clinical cardiology.

In the US Cardiovascular Health Study, the Cognitive sub-study looked at the relationship between the common cardiac risk factors, depression and dementia – both of which have been postulated to have an association with underlying vascular disease6. A 2,220 sample of patients with normal cognitive function were studied. Depressive symptoms at baseline were associated with an increased risk of Mild Cognitive Impairment (MCI: 10.0 per cent, 13.3 per cent, and 19.7 per cent for those with none, mild, and moderate or severe depressive symptoms, respectively).

This association was diminished only slightly by adjustment for vascular disease measures and demographics. However, vascular disease measures were also associated with an increased risk of MCI, and these associations were not diminished by adjustment for depressive symptoms or demographics. This suggests that depressive symptoms are independently associated with an increased risk of MCI. What is not clear is whether aggressive treatment of the depression at this stage would impact on the impending cognitive disorder.

Depression and other illnesses

Peripheral vascular disease affects approximately 20 per cent of the age 65 years and older group. Depressive symptoms occur in 30 per cent to 60 per cent of these patients and are frequently unrecognised by the treating physician7.

Depression post stroke is also a frequent condition and it is receiving more attention. Post-stroke depression is estimated to occur at a frequency between 18 and 60 per cent. Several methodological problems regarding inclusion criteria (acute versus chronic patients, exclusion of demented and aphasic patients), the type of scales used (self applied scales, diagnostic and statistical manual of mental disorders criteria interview, Hamilton, etc.) limit direct comparison between the published studies, but characteristic features of post stroke depression appear to be in three areas: cognitive, affective and somatic8.

Studies in the treatment of these depressive symptoms imply that minor symptoms usually resolve spontaneously within six weeks – whereas moderate to severe symptoms will require antidepressant therapy.

Psychological adjustment to chronic heart failure is often poor, with the prevalence of depression in out-patients ranging from 13 per cent to 48 per cent. In a study in Leeds, the prevalence rates of anxiety and depression were 18.4 per cent and 28.6 per cent, respectively9. Predictors of depression included a reported history of mental ill-health; whereas predictors of anxiety included a reported history of mental ill-health plus co-morbid physical illness (diabetes and angina). Interestingly, the severity of heart failure did not predict either anxiety or depression. Identifying the risk of poor psychological adjustment in patients with heart failure may assist in targeting bio-psychosocial intervention for patients most at risk of anxiety and depression within community disease management programmes.

Painful physical symptoms commonly exist co-morbidly with depressive disorders and may complicate the diagnosis of underlying depression10. Patients tend to discuss physical pain with physicians but not emotional pain, not realising they may be aspects of the same disorder. Those presenting with somatic complaints are three times less likely to be accurately diagnosed than patients with psychosocial complaints. 

Abnormalities of serotonin and noradrenaline are strongly associated with depression and are thought to also play a pivotal role in pain perception. Brain-derived neurotrophic factor, which is increased with antidepressant treatment, appears to influence both regulation of mood and perception of pain. Clinical trials have shown that antidepressants that act on both of these transmitter systems appear to modulate pain better than those agents that increase either serotonin or noradrenaline alone. Thus dual-acting agents (such as venlafaxine, mirtazapine and duloxetine) are better suited in these situations, including the difficult to treat neuropathic pain. However these agents are rarely used by general hospital doctors, who often use the less well tolerated tricyclic antidepressants.

Depression is common in Parkinson’s disease (PD) with prevalence rates of up to 50 per cent for all types of depressive symptoms11. Depression in PD has been associated with female sex, previous depressive illness, earlier onset and right-sided motor symptoms. Diagnosis of depression can be challenging as symptoms like psychomotor slowing, insomnia, fatigue and poor concentration are features of PD as well as depression.

The PD specialists are more successful at picking up depression, resulting in approximately a quarter of PD patients being on an antidepressant at any one time12 – usually a Selective Serotonin Reuptake Inhibitor (SSRI), although there are no randomised studies to support this. The dopamine agonist pramipexole has shown antidepressant properties in randomised studies and could be considered if an agonist is required for the motor disorder as well.

These few examples show how pervasive depression is amongst the common medical conditions. Other examples that could have been cited include diabetes and cancer – and depression is also implicated in falls. This means that for geriatricians, depression affects all their major cornerstones and is a key illness to understand. It is fairly clear that patients with depression and these co-morbid conditions usually respond to antidepressants as well as patients without the co-morbid problems13. Also these patients (those with depression and co-morbidities) frequently reattend if unidentified or inadequately treated. In a UK primary care study, the prevalence of frequent attendance in the elderly was 22.4 per cent associated with depression even after controlling for physical illness and unexplained somatic complaints14.

Table 1. Patients most likely to be at risk of depression 

  • Frequent attenders, especially if weekly or more > Patients with existing mental health problems
  • Patients on benzodiazepines
  • Carer in difficult caring situation
  • Carer whose role has recently ceased or significantly changed
  • A diagnosis of carcinoma of the lung and pancreas
  • A patient with chronic respiratory disease
  • Patients who are recovering from cardiovascular and cerebrovascular incidents.

Table 2. General guidance for treatment options

  • Where patients have had an episode of depression previously and responded to a treatment, this should be the first choice of action in a new episode
  • SSRIs are considered first line in cardiovascular and cerebrovascular disease – because of better tolerability and safety
  • Antidepressants work in depression after stroke, but spontaneous remission is common within six weeks
  • Tricyclics are generally considered too toxic for the elderly (but should be considered if successfully used previously)
  • Benzodiazepines are not antidepressants – but may have a role in treating concomitant anxiety
  • Psychological intervention often can play a synergistic role and should be considered for each case and offered where available – age is not a barrier to psychological therapy

Improving the situation

Simple steps to improve the current situation include raising awareness of depression in non-specialist staff (Table 1).

Another way of increasing identification is to use a simple screen for depression, which comprises the following two questions:

  1. During the last month, have you been bothered by feeling down, depressed or hopeless?
  2. During the past month, have you often been bothered by little interest or pleasure in doing things?

If a case of depression is identified, then several principles need to be applied. Firstly, there is the need to treat the whole person – including their physical and psychosocial needs. Following this, there is also the need to educate patients and carers about depression and their treatment options.

The aim of treatment should be a remission of symptoms (i.e. reaching a stage where troublesome symptoms no longer continue) and not just a response to treatment (i.e. a lowering of symptomatology persisting symptoms). Clinical studies suggest a response is three times easier to achieve than remission.

In terms of which treatment to choose, there is no evidence that any one antidepressant is more effective than another – either for the depression or any co-morbid anxiety or insomnia. There is also no evidence that there are differences in speed of onset of any of the antidepressants. Treatment and maintenance must be at the therapeutic dose of the drug chosen – low dose antidepressant treatment is not recommended in the older depressed patient (Table 2).

A placebo controlled trial of interpersonal therapy has shown it is effective on minor depression in the general hospital population15. This is a relatively easy therapy to learn and could be a valuable addition to the skills of the clinical hospital staff.

Conclusion

Depression is a common condition in the general hospital, existing alongside many physical conditions in a complex and inter-related way. Exact mechanisms may not be well understood at present, but proper identification and treatment of depression does have a major impact on health outcomes. It is therefore essential that all clinical staff who are involved in the care of older people have the requisite skills to identify and implement treatment for this condition.

References

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  2. Working group for the Faculty of Old Age Psychiatry (2005). Who cares wins. London. Royal College of Psychiatrists
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