Prevalence in older people

In a meta-analysis the prevalence of clinically significant depression among older people living in the community was 13.5% (Reference Beekman, Copeland and PrinceBeekman et al, 1999). Important determinants of prevalence are disability and handicap so, unsurprisingly, rates are at least doubled among patients in hospital or nursing homes. There are possible neurobiological links between depression and stroke, Parkinson’s disease and the dementias (vascular dementia having the highest rate of comorbid depression), but also a high rate of depressive symptoms in a range of chronic medical disorders, including heart disease (Reference Ariyo, Haan and TangenAriyo et al, 2000) and chronic obstructive pulmonary disease (Reference Yohannes, Roomi and BaldwinYohannes et al, 1998).

Assessing depression in later life

Special factors to take into account when assessing depression in older people are listed in Box 1. The skills of history-taking, conducting a mental state examination, physical evaluation and organisation of relevant investigations are no less important than in other branches of psychiatry. Given the increased likelihood of finding an organic condition contributing to depression with advancing age, these skills are arguably more important. Boxes 2 and 3 list the more important causes of organic depressive episodes.

Screening

The most widely validated screening instrument is the Geriatric Depression Scale, introduced in 1983 (Reference Yesavage, Brink and RoseYesavage et al, 1983). Short and long versions and translations of the scale are available at http://www.stanford.edu/~yesavage/GDS.html. The 15-item version (with its 4- and 5-item derivatives) is shown in Box 4. The 5-item version has recently been validated in a sample comprising individuals living in the community, hospitalised patients and nursing-home residents (Reference Rinaldi, Mecocci and BenedettiRinaldi et al, 2003).

Box 4 The 15-item Geriatric Depression Scale, also showing questions for the 4- and 5-item scales

Instructions: Choose the best answer for how you have felt over the past week.

1	Are you basically satisfied with your life?	Yes/No	(No)
2	Have you dropped many of your activities and interests?	Yes/No	(Yes)
3	Do you feel your life is empty?	Yes/No	(Yes)
4	Do you often get bored?	Yes/No	(Yes)
5	Are you in good spirits most of the time?	Yes/No	(No)
6	Are you afraid something bad is going to happen to you?	Yes/No	(Yes)
7	Do you feel happy most of the time?	Yes/No	(No)
8	Do you often feel helpless?	Yes/No	(Yes)
9	Do you prefer to stay at home, rather than going out and doing new things?	Yes/No	(Yes)
10	Do you feel you have more problems with your memory than most?	Yes/No	(Yes)
11	Do you think it is wonderful to be alive now?	Yes/No	(No)
12	Do you feel pretty worthless the way you are?	Yes/No	(Yes)
13	Do you feel full of energy?	Yes/No	(No)
14	Do you feel that your situation is hopeless?	Yes/No	(Yes)
15	Do you think most people are better off (in their lives) than you are?	Yes/No	(Yes)

Questions 1, 2, 6 and 7 make up the 4-item version.

Questions 1, 4, 8, 9 and 12 make up the 5-item version.

The answers shown in parentheses indicate possible depression.

Possible cut-offs: ≥ 5 for the 15-item version; ≥2 for the 4-item and 5-item versions.

Types of depression in older people

Prognosis

Reference Cole and BellavanceCole & Bellavance (1997a) reported that after an index episode about 60% of secondary care patients either remained well or had treatable relapses. About 1 in 5 developed chronic symptoms. Outcome for individuals living in the community was worse. In another meta-analysis of depressed patients in acute medical and surgical care, only about 1 in 5 recovered (Reference Cole and BellavanceCole & Bellavance, 1997b ). Low rates of detection and undertreatment may partly explain these poor results (Reference BaldwinBaldwin, 2000).

Katona’s statement in an earlier review (Reference KatonaKatona, 1996) still holds true: depression in old age is associated with chronicity and a high risk of relapse after recovery. However, this is just as true for younger adults, prompting current interest in managing depressive disorder within a chronic disease model (Reference Rost, Nutting and SmithRost et al, 2002).

Mortality is high in older patients with depression, largely because of concurrent physical disorder (Reference TumaTuma, 2000).

Principles of management

The management of depressive disorder in older people should be multimodal (involving physical and psychological modalities along with social interventions) and multidisciplinary (with help from specialists such as nurses, social workers and occupational therapists, and help as needed from dieticians, speech and language therapists and podiatrists). Some broad goals of treatment and ways of achieving them are shown in Table 1 (Reference Baldwin, Chiu and KatonaBaldwin et al, 2002). Handicap, the social disadvantage caused by illness, is closely associated with depression in old age. Thus, social factors such as the availability of transport and crime reduction may have very positive effects on reducing rates of depression.

Treatments that work are the same as for younger adults: antidepressants, psychosocial and psychological interventions, or combinations of these (Reference Anderson, Nutt and DeakinAnderson et al, 2000), and ECT.

Drug treatment

Pharmacodynamics and pharmacokinetics alter with ageing and are also affected by concomitant medication and physical illness. Older people exhibit marked inter-individual variation in how medication is metabolised. This can lead to difficulty in predicting the target dose. The adage ‘start low, go slow’ then applies. This is less of a problem with the newer antidepressants, for which the starting dose and the therapeutic dose are identical. However, therapeutic trials often exclude the very old and the very frail, so that our knowledge is incomplete. Although many newer antidepressants require no dose adjustments for older patients, impaired renal or hepatic function necessitates caution with all antidepressants. Table 2 lists the main antidepressants, starting doses and average dosages for older patients by consensus (Reference Alexopoulos, Katz and ReynoldsAlexopoulos et al, 2001; Reference Baldwin, Chiu and KatonaBaldwin et al, 2002), along with side-effect profiles.

Older patients take longer to recover. Whereas 4 weeks may be a sufficient time in which to see a response in younger adults, 6–8 weeks or longer may be more typical for older patients. Nearly 20 antidepressant drugs are currently available for use in the UK. With such a wide variety of antidepressants it is best to tailor the drug to the patient, the choice being determined by symptom profile, tolerance and the likelihood of drug interactions or side-effects.

Psychological interventions

Older patients with depression are rarely offered a psychological intervention. Changing attitudes and increased awareness are likely to alter this. In a large primary-care-based study in which a treatment choice was offered to older patients with depression, 50% expressed a preference for a psychological approach over drugs (Reference Unützer, Katon and CallahanUnützer et al, 2002). Additionally, there is emerging evidence that for older adults with mild-to-moderate depressive episodes a psychological intervention is as effective as medication (Reference McCusker, Cole and KellerMcCusker et al, 1998; Reference Pinquart and SorensenPinquart & Sorensen, 2001). Whether services are adequately configured to meet the need is more questionable. Nevertheless, in England, the National Health Service Executive’s strategic review of psychotherapy services has endorsed the need for accessibility and equity across patient groups (National Health Service Executive, 1996). General areas of importance when working psychodynamically with older people have been addressed in a previous APT article (Reference GarnerGarner, 2002).

Cognitive–behavioural therapy (CBT) is the best-established treatment in depression and good evidence exists for its effectiveness in older adults (Reference Thompson, Coon and Gallagher-ThompsonThompson et al, 2001). However, most studies have looked at its use in cognitively intact and medically stable patients and so its effectiveness outside this patient group is not fully established. Small studies and case reports have indicated that CBT can be adapted for use with physically frail patients and those with mild cognitive impairment, but further research is needed. Interpersonal therapy is also effective in relapse prevention (Reference Reynolds III, Miller and PasternakReynolds et al, 1999a ,Reference Reynolds III, Frank and Perel b ). There is a smaller but developing evidence base for problem-solving treatment (Reference Arean, Perri and NezuArean et al, 1993; Reference Unützer, Katon and CallahanUnützer et al, 2002). In major depression, a combination of antidepressants with psychotherapy is more effective than either of these treatments alone, especially in relapse prevention (Reference Reynolds III, Frank and PerelReynolds et al, 1999b ; Reference Thompson, Coon and Gallagher-ThompsonThompson et al, 2001). Psychoeducational techniques have also been used in this age group with good effect. For example, in one recent study a group course on coping with depression and anxiety was effective in reducing scores on the Geriatric Depression Scale (Reference Schimmel-Spreeuw, Linssen and HeerenSchimmel-Spreeuw et al, 2000).

Lastly, family therapy has been successfully adapted for use with older adults, including those with depression (Reference Benbow, Egan and MarriottBenbow et al, 1990), but no controlled data have been published regarding efficacy.

Electroconvulsive therapy

Electroconvulsive therapy remains the most effective treatment available for severe depression, with a recovery rate in the region of 80%. It is well tolerated, even by very elderly people (Reference Tew, Mulsant and HaskettTew et al, 1999). Its use is generally reserved for when there is a threat to life due to insufficient dietary intake or suicidal behaviour, or if treatment with antidepressants has been ineffective. There is evidence that it is particularly effective in psychotic depression (Reference Baldwin, Chiu and KatonaBaldwin et al, 2002). There are no absolute contraindications, but a review of medical risk by a senior anaesthetist is advisable. Wherever possible hypertension and cardiac failure should be treated optimally before ECT. It should be avoided in the first 3 months following a myocardial infarction or stroke. Elderly patients are more likely to suffer post-ECT confusion and cognitive impairment and therefore this should be carefully monitored during treatment. Memory impairment is often worse with bilateral electrode placement although the response to bilateral treatment may be more rapid.

Other treatments

Rapid transcranial magnetic stimulation (rTMS) is a promising new treatment for depression. The early evidence suggests that it may be less effective in older adults, especially in the presence of even mild frontal atrophy (Reference Manes, Jorge and MorcuendeManes et al, 2001). St John’s Wort, a herbal remedy, is popular but lacks a satisfactory evidence base. Epidemiological data support a link between depressive symptoms and lack of exercise in older people (Reference Baldwin, Chiu and KatonaBaldwin et al, 2002), but data have not been published on the use of exercise as a treatment for late-life depression.

In an important study designed to replicate models of enhanced care (also known as ‘stepped care’) developed for use with younger patients in primary care, Reference Unützer, Katon and CallahanUnützer et al(2002) showed that a multifaceted intervention for depression was more effective than usual care for older adults. The model chosen emphasised case management, the use of antidepressants and/or problem-solving treatment, and improved links between primary and specialist care.

Treatment-resistant depression

Although definitions of treatment resistance vary, at least 30% of elderly patients with depression do not respond to first-line treatment with an antidepressant (Reference McCusker, Cole and KellerMcCusker et al, 1998). The initial steps are to ensure that a medical cause for depression has not been overlooked, that the patient tolerates and takes the medication and that the dosage is optimal.

New data suggest that if the patient has shown little or no response (in objective terms less than a quarter improvement on an appropriate rating scale) within the first 4 weeks at therapeutic dosage, recovery is unlikely (Reference Mottram, Wilson and AshworthMottram et al, 2002). The best course is to change to an antidepressant of a different class. If, however, there has been a partial response, the clinician is faced with a choice. Other things being equal, because older patients take longer to recover (Reference Anderson, Nutt and DeakinAnderson et al, 2000), waiting and supporting the patient may be a reasonable course of action. Otherwise, the advantages and disadvantages of augmentation and substitution, the two main strategies open to the clinician, are outlined in Box 5 (augmentation refers to adding another treatment to the original medication).

Clinicians in the UK tend to be ‘swappers’ – from one class of antidepressant to another. The use of non-reversible monoamine oxidase inhibitors as an option has gone out of favour, although there was an early evidence base for their efficacy. Another approach, of combining a tricyclic with an SSRI, has given way to the newer dual-acting antidepressants such as venlafaxine or combinations such as SSRIs with mirtazapine. Both have some evidence to support their use in resistant depression (Reference AndersonAnderson, 2003), although not specifically in older people. The high doses of venlafaxine sometimes recommended are not always tolerated by older patients. Likewise, augmentation with lithium has a reasonable evidence base, but tolerability can be a significant problem in older patients. Serum monitoring is required.

Maintenance treatment

How long to continue with maintenance therapy is not yet clear. A recent expert consensus statement suggests that after a first episode of major depression a majority of clinicians opt to keep the patient on continuation treatment for at least 1 year. For two episodes there was less agreement, but for patients with three or more relapses or recurrences most clinicians recommended long-term treatment (Reference Alexopoulos, Katz and ReynoldsAlexopoulos et al, 2001). As with other age groups, it is important to maintain the patient on the same medication regimen that led to remission.

Surprisingly, one would be hard pressed to find any evidence to show that the new range of antidepressants developed over the past 20 years has led to an improved prognosis for late-life depression. However, there is more optimism with respect to prevention. Once a patient has recovered, there is good evidence that ongoing treatment with a tricyclic (Old Age Depression Interest Group, 1993), the SSRI citalopram (Reference Klysner, Bent-Hansen and HansenKlysner et al, 2002) or a combination of medication with a psychological treatment (Reference Reynolds III, Frank and PerelReynolds et al, 1999b) are effective. In a recent trial, sertraline at conventional therapeutic dosage was not effective in preventing relapse in older community-dwelling patients over a period of 2 years (Reference Wilson, Mottram and AshworthWilson et al, 2003). Therefore, it cannot be assumed that all antidepressants are equally effective in prophylaxis.

Multiple choice questions

1. 1 Depressive disorder in older people:

   1. a is prevalent in 1 in 100

   2. b strongly predicts later dementia

   3. c affects almost half of patients with Parkinson’s disease

   4. d is more common in vascular than in Alzheimer’s dementia

   5. e often presents with hypochondriasis.

2. 2 Management principles include:

   1. a symptom improvement as the main goal

   2. b dietary advice

   3. c assessment of self-neglect

   4. d a serum ferritin level

   5. e detailed neuropsychological examination.

3. 3 Treatment:

   1. a always starts with an SSRI

   2. b should be changed if there has been a 25–50% response at 4 weeks

   3. c with cognitive–behavioural therapy is an effective alternative to antidepressants for moderate depression

   4. d of mild cases with a combination of medication and a psychological intervention is more effective than either alone

   5. e with ECT is hardly ever effective in the ‘old-old’.

4. 4 Prevention:

   1. a of relapse requires treatment for about 6 months at most

   2. b of recurrence has been demonstrated only for tricyclic antidepressants

   3. c of recurrence after a third episode is an indication for long-term antidepressant treatment

   4. d of recurrence in moderate-to-severe depression is best achieved by combining an antidepressant with interpersonal therapy

   5. e of depression should include attending to handicap.