There is no mental disorder that is inevitable in old age. Older people describe their overall well-being as good. Hence there is such a thing as “normal” ageing in terms of mental (as well as physical) health. Nevertheless, as in all age groups, mental disorder is not uncommon in older people and there are some disorders that become more prevalent as age increases. Mental disorder in old age can be divided into two broad categories:

• Organic disorders

These are characterized by confusion, which may be acute (i.e. delirium) or chronic (i.e. dementia);

• Functional disorders

Such as depression, anxiety and panic; but also psychotic disorders, such as late-onset schizophrenia (formerly known as “late paraphrenia”)

In addition, drug and alcohol misuse and dependence can (like many disorders) continue into old age, or emerge for the first time when the person is older. Similarly, it should not be forgotten that personality difficulties do not necessarily disappear with ageing. (Wolstenholme et al, 2002)

Epidemiology

The prevalence of mental disorder in elderly people depends on exactly which age group is examined and where they are living. In community surveys of all people aged over 65 years, approximately 5% are found to have severe organic brain disorders (mainly dementia) and a further 5% to have mild symptoms of forgetfulness. 2.5-5% will have depression severe enough to warrant treatment with a further 10% complaining of minor depressive/anxiety symptoms. Late onset schizophrenic illnesses are much less common, perhaps 0.5-1.0%. (Landau et al, 2008)

If one looks at the very elderly (greater than 80 years) the rates of organic disorders, mainly dementia, are much increased, (e.g. 20%) whereas other diagnoses may occur less frequently – in other words organic disorder is (as one might expect) a disorder associated with increasing age.

In residents in local authority homes, hospitals or other institutional care, the rates for both organic and functional disorder (particularly depression) are much increased – about 30% for each type. It is probable that mental disorder will have contributed to the person entering the institution, e.g. dementia making them unable to survive safely in their own home – but the combination of losing one’s home and familiar surroundings can also aggravate existing confusion and/or depression. (Landau et al, 2008)

Ethics and Law

The main ethical concern in older people relates to the issue of capacity. In some jurisdictions (e.g. Scotland) there are now laws around incapacity. Capacity legislation will appear shortly in England and Wales. Irrespective of the legislation, however, the need to maintain the older person’s ability to make autonomous decisions is clearly of ethical importance. Autonomy can be undermined by both professionals and families for both benign and malignant reasons (Colin, 2008). The presumption should always be that the person has the capacity to make a particular decision. Judgements about capacity should always be made with respect to a specific ability: a person may not be able to drive, but may still be able to run his or her own finances. Having a particular capacity (or competence) means that the person can recall and understand the relevant information and that the person shows evidence of weighing up the information as he or she makes a decision (which need not be the decision that the person assessing capacity would have reached). (Colin, 2008)

If the person lacks capacity, those involved must act in the person’s best interests. These have to be understood broadly. The criteria for assessing a person’s best interests should include: taking account of what the person has said or stipulated (e.g. on an advance directive or “living will”) in the past; taking account of what the person now says when enabled to participate in the decision; taking account of the views of all those other people involved in the person’s welfare, insofar as this is practicable, especially as regards what they think the person’s wishes would have been under the present circumstances if the person had been able to express his or her wishes; making sure that the least restrictive course of action is taken.

There are particular procedures to be followed if the person lacks certain capacities. For instance, there is a variety of steps to be taken (involving the Court of Protection) when the person cannot manage his or her finances; and if the person lacks the capacity to drive, the requirements of confidentiality may be put aside in the interests of public safety. Having said this, however, the doctor’s duty is to be on the side of the patient and it is an affront to the person’s standing as an autonomous individual if his or her abilities are undermined without due cause. The General Medical Council offers advice on such issues. (Van, 1996)

The Aging Population

The table (based on 1991 projections) shows the age structure of the UK population for the years 2001 to 2041. The increase in the proportion of elderly people is in the 75-84 year group (+39%) and more particularly in those 85+ years (+55%). Meanwhile, the numbers of younger people changing little. The vast majority of these older people live at the present time in their own homes, only 6% being in institutional care (residential homes or hospital).

The over-85 group are predominantly women, the majority widowed and living alone. The very elderly group have high consultation rates with general practitioners, with many more home visits and occupy up to 50% of all NHS beds (medical, surgical and psychiatric). They are more likely to have complex combinations of physical, psychological and social difficulties, which require multidisciplinary assessment and treatment. (Birk and Harvey, 2006)

Dementia

About 5% of the general population over 65 years suffer from severe cognitive impairment with further 5% showing mild changes, which may progress with time. Dementia refers to a global impairment of mental function which follows a chronic and progressive course. The symptoms and signs have usually been present for at least 6 months (Birk and Harvey, 2006). The impairment of mental function is commonly associated with deterioration in emotional control, social behaviour, motivation and the ability to perform activities of daily living (ADLs). These “non-cognitive” features of dementia, which are often the most upsetting aspects for family carers and friends, tend now to be referred to as Behavioural and Psychological Symptoms in Dementia (BPSD). Dementia is related to progressive cerebral degeneration, which may be caused by a variety of pathological processes, such as Alzheimer’s disease, vascular dementia and dementia with Lewy bodies. Post mortem changes found in the brains of people with dementia suggest the following diagnoses (approximate figures):

Alzheimer’s disease

50%

Vascular dementia

15%

Dementia with Lewy bodies

15%

Mixed vascular/Alzheimer’s disease

15%

Other causes

5%

Alzheimer’s disease

Alzheimer’s disease is characterised by a gradual insidious onset and progressive course, often beginning with memory failure before other cognitive functions (e.g. language, praxis) become affected. Non-cognitive features (depression, psychosis, wandering, aggression, incontinence) are common. Physical examination is often normal, as are routine blood investigations. (Farrer, 2001)

Computerized tomography (CT) scans may be normal or show generalised atrophy and dilatation of ventricles. CT scans also play a role in excluding other possible causes of confusion (e.g. space-occupying lesions, haemorrhages). Angled CT scans afford better views of the medial temporal lobes, which can show marked atrophy. However, this is not specific for Alzheimer’s disease. Hippo-campal atrophy is also seen with magnetic resonance imaging (MRI) scanning. Single photon emission computerized tomography (SPECT) provides information on how the brain is functioning, usually by tracing blood flow using radio-labelled technetium. In Alzheimer’s disease SPECT scanning can show a generalized decrease in blood flow, or biparietal and bitemporal hypo-perfusion. However, the diagnosis must always be made on the basis of the overall clinical presentation rather than solely on the appearance of scans. (Farrer, 2001)

Dementia with Lewy bodies

Dementia with Lewy bodies is characterised by the triad of fluctuating cognitive impairment, recurrent visual hallucinations and spontaneous Parkinsonism, though not all occur in every patient. As with Alzheimer’s disease, onset is insidious and may begin with cognitive problems, Parkinsonism, or both. Cognitive impairment initially affects attentional and visuo-spatial function, with memory initially relatively spared. As with Alzheimer’s disease, non-cognitive features are common. Parkinsonism consists mainly of bradykinesia rather than tremor and, once again, routine blood investigations are normal. CT scan may be normal or show generalised atrophy and dilatation of ventricles, with less temporal lobe atrophy than in AD. Blood flow SPECT can show similar changes to those seen in Alzheimer’s disease, though DLB is more likely to be associated with occipital hypoperfusion than Alzheimer’s disease, a finding which may relate to the hallucinations and visuospatial disturbance. Parkinsonism in DLB is associated with nigrostriatal degeneration, similar to that seen in Parkinson’s disease. It is possible to image nigrostriatal degeneration using SPECT scanning with a ligand for the dopamine transporter (FP-CIT or “DaTSCAN” imaging) which can be helpful in assisting with the diagnosis of Parkinson’s disease. In the future it is hoped such imaging methods may be helpful in diagnosing DLB as well. (Mo Ray, 2009)

Vascular dementia

In contrast, vascular dementia usually has an abrupt onset, often in association with a recognised stroke, and is associated with a fluctuating course, a stepwise decline and often reasonable insight at least in the early stages of illness. An exception to this course is subcortical vascular dementia, which may cause some 20% of all vascular dementia, when sudden onset and a stepwise course may not be seen. Patients will often have risk factors for vascular disease, for example high or low blood pressure, ischaemic heart disease or peripheral vascular disease, but also diabetes mellitus and hypercholesterolaemia. Physical examination is likely to reveal focal neurology and a CT scan would be expected to show evidence of cerebrovascular disease. (Mo Ray, 2009)

Other dementias

Other causes include rarer degenerative processes, e.g. Fronto-temporal dementia, Huntington’s disease, in addition to alcoholic dementia, tumours, haematoma, etc. In some cases no discernible pathology is found. (Mo Ray, 2009)

Clinical assessment and management

By careful history taking (usually from patient and informant) and examination of both physical (particularly neurological) and mental state, it is possible to predict the likely underlying pathology in most patients with dementia. No specific diagnostic tests are yet available, but clinical diagnosis may be usefully supported by structural brain imaging methods such as CT or MRI scanning and functional imaging techniques such as SPECT (Single Photon Emission Computer Tomography) scanning. It is important to develop methods of establishing the aetiology of dementia during lifetime (Eastwood and Reisberh, 1996):

• To assist in predicting course of illness and determining prognosis.

• To inform management decisions; for example specific treatments are becoming available for Alzheimer’s disease (cholinesterase inhibitors) and vascular dementia and it is necessary to know which patients should receive which treatment.

Patients with dementia usually present either because of failure to cope or with disturbed behaviour occasionally with both. They often lack insight into their illness or, in the early stages, deny it. People with dementia require:

• An assessment of the cause and severity of the dementia (cognitive impairment and behavioural abnormalities);

• An assessment of deficits in function and the need for care (dependency);

• An assessment of the person’s social situation;

• Provision of treatment and care appropriate to the identified needs;

• Support for carers – both practical and emotional;

• Review of the above points – is the treatment and care appropriate and beneficial?

About 50% of cases of dementia have concurrent physical health problems. The burden of care produced by a physically sick patient with dementia is greater than that of a fit one; therefore, diseases should be sought and treated where appropriate. Dementia may also be complicated by:

• Emotional liability

• Depression

• Psychotic features (i.e. delusions and hallucinations)

• Behavioural disturbances (i.e., wandering, aggression, incontinence)

These may be helped by pharmacotherapy, counselling and explanation and support to relatives. Such patients may respond either to antidepressants for liability and depression, or antipsychotic agents for psychotic features and some behavioural disturbances. Patients with dementia are often sensitive to side effects of psychotropic drugs and so it is important to begin therapy with very low doses of medication and monitor carefully for side-effects, particularly extra-pyramidal problems. In 2004, the two drugs Risperidone and Olanzapine were recommended not to be used for the control of agitation and disturbed behaviour in dementia because of the risk of stroke. The use of antipsychotic medication to control agitation and other difficult behaviours in moderate to severe dementia remains common but controversial. (Birk and Grimley, 2005)

Memory Clinics

The assessment of forgetfulness is often undertaken by memory clinics. These exist in a variety of forms (some being very clinically focused and others having a research basis). The aim is to provide thorough assessment (clinical history, with mental state, neuropsychological and physical examinations and appropriate investigations e.g. blood tests and neuro-imaging) in order to arrive at an accurate diagnosis. Some clinics then initiate and monitor the use of medication (e.g. the cholinesterase inhibitors for Alzheimer’s disease). Increasingly, memory clinics are seeing people with milder symptoms, many of whom will be anxious about the possibility of dementia. Some such patients will have other conditions, such as depression (i.e. “pseudo-dementia”) or other physical illnesses. (Seltzer et al, 2004)

The diagnosis of “mild cognitive impairment” (MCI) is now sometimes made in people who present with forgetfulness but who do not satisfy the criteria for even a mild dementia (because, for instance, their everyday activities are not impaired). A proportion of people given the diagnosis of MCI will progress to develop dementia on followed-up. Identifying MCI may, therefore, open up the possibility of early treatment. But MCI is not uncontroversial, because some people given this label will show no such progression of symptoms and might be more properly regarded as “normal”. (Seltzer et al, 2004)

Acute Confusion (Delirium)

Elderly people seem particularly likely to develop confusion in response to a wide range of stimuli – either physical insults or sudden social change. This presumably reflects the reduced ability of the aged brain to cope with such events, particularly if it is additionally damaged by a dementing process. An acute confusional episode may sometimes be the first evidence of an underlying dementia. Elderly patients with acute confusion are seen throughout medical practice, e.g. 20% of all acute medical ward admissions are found to be acutely confused. In elderly people apathy, under-activity and clouding of consciousness are more common presentations of delirium than the florid, overactive restless, hallucinating states usually described in relation to younger patients. Causes include (Birk et al, 2006):

• Intercurrent physical ill-health

•Adverse reaction to a prescribed drug or drugs

•Catastrophic social situations, e.g. a move into residential care

Acute confusion should be regarded as indicative of underlying disease and investigated medically. Untreated it has a 40% mortality rate.

The clinical approach is to complete a full physical examination looking for evidence of infection, stoke, MI or other illness. A review of medication should focus on drugs started or stopped recently. Until the underlying cause is determined and treated, a small dose of an antipsychotic agent may reduce the severity of delirious episodes. (Birk et al, 2006)

Functional Disorders

Depression

This is the most common psychiatric disorder found in old people (if milder cases are counted) and the second commonest single underlying cause for all GP consultations for people over 70. The majority of depressive syndromes are of mild to moderate severity. About one fifth of cases are severe and carry the risk of suicide – especially in men, in those which fail to remit within 6 months of onset and in those who feel physically ill (hypochondriacal) especially if they have the delusional belief that they suffer from cancer. Depression in old age may be precipitated by adverse life circumstances: bereavement; loss of health; threat of bereavement or loss of health in a key figure. As with younger patients, those who suffer from depression may have vulnerable personalities (i.e. they may be anxious and obsessional by nature) or they may have no close confidantes (i.e. they may be socially isolated). More recently evidence has emerged suggesting that depression occurring for the first time in later life may be associated with subtle brain abnormalities, such as an increase in white matter lesions (detected on neuroimaging), which may reflect hidden or undetected cerebrovascular disease. (Rands et al, 2006)

Depressive illness in old people shows a wide range of clinical presentations. The typical picture of low mood, anhedonia and vegetative disturbance of sleep and appetite seen in younger people may predominate. Some patients become apathetic, withdrawn and appear to lose their cognitive abilities (this is called depressive “pseudo-dementia” as cognitive impairment may be so marked as to mimic organic dementia). Others may present with a picture of severe agitation and restlessness, accompanied by delusions of ill health or poverty, e.g. that they are dying of a brain tumour, that their bowels have stopped working and are rotting inside them, or that they are unable to pay for their hospital treatments.

The clinical approach with mild cases of depression is unlikely to involve the Old Age Psychiatry Service, since they will be treated by the Primary Health Care Team. Support and counselling may be supplemented by the use of antidepressants. More severe or persistent cases are likely to be referred for specialist assessment and treatment. The majority of cases respond as well to treatment as younger patients – perhaps even better! Poor outcome is often the consequence of inadequate treatment. The older tricyclic antidepressants are often not well tolerated, postural hypotension, urinary and gastrointestinal side effects being prominent. (Rands et al, 2006)

Dosage should be titrated to the maximum tolerated, starting doses generally being 1/3 – 1/2 of those for younger patients. Newer antidepressants such as SSRIs have a particular place in the treatment of the elderly. Delusional depressions require the addition of neuroleptics – for unresponsive or severe depressions ECT is a safe and effective treatment. Lithium carbonate has a valuable place in prophylaxis of recurrent episodes and is also effective in potentiating or augmenting the antidepressant actions of tricyclics.

Many elderly depressed patients have previous or current physical illness. Not only must this be taken into account during treatment (e.g. tricyclic antidepressants are usually avoided in a patient with ischaemic heart disease and, in patients with a high risk of bleeding, SSRIs should be used with caution), but also physical illness must be treated in its own right to maximise the patient’s chances of recovering from the depression. (Rands et al, 2006)

Anxiety Disorders

Anxiety disorders do occur in old people, about half of it persisting from early life and half coming on for the first time in response to the stresses of ageing. A common precipitant stress is that of failing physical health, e.g. developing an acute phobic state after a fall from a bus, leading to a fracture and a period of reduced mobility.

Behavioural methods of treatment may be effective. Diffuse anxiety and loss of confidence, even if precipitated by an adverse event, may indicate an atypical form of depression. Such patients respond better to antidepressant, rather than anxiolytic, drugs. (Rands et al, 2006)

Paranoid States

It appears to be a normal feature of ageing that individuals become rather more inflexible in their attitudes and fearful of adverse influence by the outside world. Elderly people are often not only physically and financially disadvantaged, but they enjoy relatively low social status and are often the victims of attack or deception. It is, therefore, perhaps not surprising that persecutory ideas (which we tend to lump together as paranoid symptoms) often emerge. The main conditions in which paranoid persecutory symptoms occur are as follows (Corey-Bloom, 2000):

Late onset schizophrenia/delusional disorder

This was formerly known as paraphrenia. The typical subject is an elderly spinster, with sensory impairments (deafness or visual impairment), living alone and isolated. Her self-care skills are good and she is apparently normal apart from the possession of a complex delusional system in which she believes she is the victim of a conspiracy (usually to defraud her). She hears third person auditory hallucinations, may smell odours, which she interprets as poison gas pumped into her room and misinterprets chance occurrences as having special significance. This psychotic illness, similar to schizophrenia in younger life, responds to antipsychotic drugs if the patient can be persuaded to take them. The delusions, however, seldom completely disappear but instead become “encapsulated”: the patient is no longer bothered by them although he or she never gains full insight into their delusional nature. A depot injection given by a Community Psychiatric Nurse is often a useful vehicle which improves compliance with medication and provides regular contact with the patient. (Corey-Bloom, 2000)

Acute confusional state/delirium

Paranoid symptoms are common during delirium, the patient misinterpreting events because of his/her altered level of consciousness. The management of these symptoms has already been described – neuroleptic medication may help to reduce agitation and behavioural disturbances.

Paranoid Reactions to Forgetfulness

These usually occur in independent old people who explain their experience of forgetting where things have been placed by accusing others of stealing them. Objects stolen are usually everyday ones, e.g. cups, teapots, pension book, money or glasses. Stolen objects often are returned or reappear in the usual place. The most likely cause of forgetfulness and paranoid misinterpretation is, of course, a dementing process. Neuroleptic medication is seldom of benefit in these circumstances. (Corey-Bloom, 2000)

Assessment Procedures

Clinical diagnosis of dementia includes identifying the cause of the cognitive impairment, which may be a treatable non-dementing process, delirium, or depression (Rockwood et al., 2007). When an illness that is associated with dementia is identified, the severity and character of cognitive impairment is commonly assessed in conjunction with the degree of illness and the potential for other psychiatric disorders such as depression (APA, 2000). Diagnostic assessments include a review of the patient’s medical history, a physical exam, and evaluation of depression, delirium, and cognitive status (Beck, Cody, Souder, Zhang, & Small, 2000). Physical assessment results may identify treatable physiological imbalances that affect cognition (Freter, Bergman, Gold, Chertkow, & Clarfield, 1998).

Referral to neurology, neuropsychiatry, or a geriatric specialist in dementia has been stated as an important element in diagnostic assessment (Beck et al., 2000). Other elements in the assessment process commonly include neuro-imaging that can support the findings of assessments, and over time, the progression of the disease (Van Der Flier et al., 2005). Studies have also indicated that research using electroencephalography (EEG) might be an inexpensive tool that could contribute to the differentiation of dementias.

Another important set of tools for assessment of cognitive deficits is neuropsychological testing (Sano, 2007). Neuropsychological assessments include testing for deficits in cognitive abilities such as current intellectual functioning, orientation, attention, verbal and non-verbal memory, verbal fluency, naming of items, and executive functioning (Petersen & Lantz, 2002). Neuropsychological testing has been suggested as providing a contribution to clinical data in diagnostic assessment for dementia, differentiating between different types of dementias, early detection of cognitive loss, and identifying potential interventions (Sano, 2007; Savla & Palmer, 2005). The diagnosis of dementia, even with the use of diagnostic tools, remains primarily based on observational data and judgment of the combined clinical data.

The process involved in dementia assessment and diagnosis can be overwhelming and has been reported as one reason for delaying diagnosis (Sternberg, Wolfson, & Baumgarten, 2000). There is also evidence that suggests that differentiating between MCI that can precede AD, and memory loss that does not have emerging pathology, poses difficulty and hesitation in requests for formal assessment (Shah, Tangalos, & Petersen, 2000). The literature also suggests that there is a strong need for individuals and families to bring their concerns forward to a physician for assessment as often the first indication that an older adult is experiencing cognitive problems occurs during a crisis situation (Boise, Neal, & Kaye, 2004; Borson, Scanlan, Watanabe, Tu, & Lessig, 2006). In AD, memory loss has been described as insidious and can include a period of concealment preceding diagnostic investigation related to a need to “preserve feelings of self-worth, identity and control” (Keady & Gilliard, 1997, p. 245). A diagnosis of dementia coinciding with a health crisis (e.g., stroke leading to vascular dementia) or with a progressive neurological disease (e.g., Parkinson’s disease) are reported more frequently because of a higher associated incidence and known relationship with these disorders (Lindsay, Hebert, & Rockwood, 1997; Wientraub, Moberg, Duda, Katz, & Stern, 2004).

The most common impetus for diagnostic evaluation is a realization of memory problems by the individual, or their family and social contacts, or associated with upsetting behaviour in social situations. Thomas and O’Brien (2002) described behavioural changes that have been reported in dementia categorized as psychotic symptoms or possible alterations in mood or motivation.

Psychotic symptoms include delusional ideas and beliefs (e.g., believing that misplaced articles have been stolen), hallucinations (e.g., seeing and speaking to people who are not physically present in a room), and misidentification of individuals (e.g., mistaking a son for a husband). Subtle changes in mood or motivation that may initially go unaddressed but increase in level of concern include apathy (e.g., lethargy), agitation (e.g., wandering, repeated dressing and undressing), aggression (e.g., verbal and/or physical, or increasing frustration with common tasks), sleep disturbances (e.g., up during the night related to distortions in sleep cycles), changes in eating habits (e.g., progressing to dependency for awareness of meal times) and personality changes (e.g., depression or unsubstantiated suspiciousness of motives of family members). Dementia and depression have been reported as the two most common medical problems in older adults (Leplaire & Buntinx, 1999). However, the association between depression and dementia severity has not been confirmed, and in some instances depression has been misdiagnosed as signalling cognitive impairment (Maynard, 2003).

Diagnostic Procedures

These are of primary importance and include both psychiatric and medical history-taking together with physical examination and mental state assessment (including cognitive examination). Investigative procedures, e.g. EEG, blood tests, CT, MRI or SPECT scans are used as necessary.

There are now operational criteria or consensus statements for the diagnosis of the main types of dementia (e.g. Alzheimer’s, Lewy body, vascular and fronto-temporal dementias), as well as for functional disorders. Many of the investigative procedures used in old age psychiatry are aimed at excluding other conditions in order to satisfy accepted international diagnostic criteria (e.g. the International Classification of Diseases, Tenth Edition, and ICD-10).

Thus, the diagnosis of Alzheimer’s disease requires that “other systemic or brain disease[s]” should be absent. This suggests the importance of blood tests (e.g. to exclude “amongst other things” vitamin B12 or folate deficiency) and brain scans (e.g. to rule out the possibility of tumours or haematomas). On the other hand, some diagnoses can be clinched by a particular finding on investigation (e.g. the finding on CT of multiple cerebral infarcts in a person whose history is in keeping with a diagnosis of vascular dementia). A functional scan, e.g. SPECT, might be a useful means to confirm a diagnosis of fronto-temporal dementia in someone where the anatomical scan (e.g. CT) only shows very mild frontal lobe atrophy. Such a scan might then be used to explain this bewildering and distressing condition to the family.

Illnesses in old age are commonly multiple, so that patients often suffer from several disorders simultaneously. Investigations become important, therefore, in functional illnesses too, not only because certain conditions need to be excluded (e.g. hypothyroidism in depression), but also because other physical conditions might make some psychiatric symptoms worse, or might preclude the use of certain medications. For example, chronic obstructive pulmonary disease, if not optimally treated, might exacerbate anxiety and panic; or a bleeding disorder or ulcer might limit the use of SSRIs.

Disorder of Function

Diagnosis alone does not tell you how severely disabled someone is. Two people with the same condition may behave very differently, e.g. dementia due to Alzheimer’s disease may render one person unsafe for independent living, but simply slow the other one down in the time taken to complete the daily crossword. It is important therefore to assess the functional disability that an old person suffers from and decide whether it can be relieved. Occupational Therapists and Physiotherapists play an important part here, but the doctor needs to be aware of this aspect of illness when he/she is taking a history. No