Symptoms of anxiety and depression occur to some extent in all of these disorders in late life. Depressive symptomatology in old age is described elsewhere (see Chapter 8.5.4). Regarding anxiety, the focus of the worries and fears of elderly people is on those issues that are of general concern in this age group (health, finances, crime). The phobias described by elderly people are similar to those seen in younger adults,⁽²⁾ although some, such as the fear of falling, are more commonly seen in old age. Clinically significant anxieties and fears in elderly people are often dismissed as reasonable purely on grounds of age. In fact, it is physical frailty and the availability of social support that determine elderly people’s perceptions of vulnerability and risk, and these rather than age should be considered when deciding whether or not concerns are reasonable.

The clinical features of OCD in old age are similar to those seen in younger patients. Obsessional symptoms rarely appear for the first time after the age of 50 years, and in such cases the possibility of an organic cause such as dementia or a space-occupying lesion should be investigated. They may also form part of a primary affective disorder.

The somatic symptoms of anxiety are similar at all ages, but in elderly patients there is a greater likelihood of misdiagnosis and inappropriate investigation and treatment. This is particularly true of elderly patients experiencing panic attacks, who tend to be misdirected to cardiologists, neurologists, and gastroenterologists.

The psychological and somatic symptoms of anxiety have several adverse behavioural consequences, for example, phobic avoidance, the abuse of sedative drugs and alcohol, and the development of troublesome abnormal illness behaviours such as somatization and hypochondriasis. In elderly patients these behaviours are usually of long standing, but they can develop following the onset of anxiety or depression in old age. In cognitively impaired patients, disturbed behaviour may be the main presenting feature.

There is extensive comorbidity between neurotic disorders and depression, and depressive symptoms are an integral component of many neurotic disorders, particularly in old age. It is therefore important to assess to what extent depression forms part of the clinical picture, as this may require treatment in its own right. Depressive disorder that is comorbid with anxiety responds less well to antidepressant treatment, and there is a greater likelihood of relapse and recurrence.

In the early stages, dementia may present with symptoms such as anxiety, and obsessionality. More commonly, anxiety and depression cause subjective cognitive impairment, which may be the presenting symptom. Dementia is associated with higher rates of anxiety, unrelated to severity of cognitive impairment. Patients with vascular dementia may be more vulnerable in this respect.

This anxiety may be associated with the implications of the diagnosis in those patients who retain insight, or a response to psychotic symptoms or misinterpretations of the external environment in those who are more severely affected. The caregivers of people with dementia are also vulnerable to developing depressive and anxiety disorders, particularly if they have a previous psychiatric history.

Although delirium is a relatively quiet disorder in elderly patients (see Chapter 8.5.1), it may be associated with significant affective disturbances, often in response to frightening visual hallucinations and imagined assaults. Conversely, in vulnerable individuals, severe anxiety may be sufficient to precipitate delirium.

Patients suffering from these disorders may experience significant fear and anxiety in response to their psychotic experiences, but this rarely causes diagnostic difficulty. Unusual hypochondriacal ideas may sometimes be difficult to distinguish from monosymptomatic delusional disorders.

There is an important association between physical illness and neurotic disorders in old age. As a life event, an episode of physical illness may be the cause of neurotic disorder, particularly if it is severe or has sinister implications. For example, mild anxiety symptoms are common following myocardial infarction in old age, and vulnerable individuals may develop a disabling ‘cardiac neurosis’ focused on their somatic anxiety symptoms. Most cases of agoraphobia that develop after the age of 65 years are not induced by panic but arise following an alarming experience of physical ill health.⁽¹⁾ Follow-up studies of stroke survivors show that conditions such as agoraphobia and generalized anxiety are common, tend to become chronic in a significant proportion of cases, and are associated with poor functional recovery.⁽³⁾ Chronic disabilities that limit mobility and independence, such as arthritis, balance disorders, and sensory impairments, increase the patient’s sense of personal vulnerability and are also associated with elevated rates of anxiety and secondary avoidance.

Neurotic disorders can also cause physical illness by direct or indirect effects on the body. In elderly people, this may come about as the result of many years of harmful anxiety-driven behaviours such as smoking and alcohol abuse.

In terms of differential diagnosis, there is also the problem that a wide range of physical disorders may present with neurotic symptoms, and vice versa. In particular, a number of important cardiovascular, respiratory, and endocrine disorders may present with anxiety or depression and little else in old age.⁽⁴⁾ Anxiety symptoms may also be caused by prescribed drugs such as oral hypoglycaemics and corticosteroids, or by excessive intake of caffeine and preparations containing sympathomimetics. In view of this, the clinical assessment should always include a drug history and a physical examination. A physical cause for neurotic symptoms should be considered if there is no past psychiatric history and no life event or other circumstances to account for their onset.