The starkest risk faced by a patient with depression is that of intentional self-harm and suicide. Careful consideration of this risk is essential in all older patients presenting with depression in whom the absolute risk of suicide has traditionally been greater than for any other age group. Particularly in the case of intentional overdose, a relative lack of medical seriousness should never be taken to indicate a lack of serious intent, and as a rule, all such cases whether ‘serious’ or not should be referred to the acute liaison or deliberate self-harm team where one is available. Self-harm in these cases should be taken to be evidence of suicidal intent until proven otherwise [17]. The factors associated with the greatest risk of completed suicide are summarised in Table 14.2 [18].

Less dramatic but also potentially life-threatening and easier to overlook are risks of self-neglect, poor nutrition and dehydration, and these areas should be given special attention in the care plan of older patients with suspected depression. Complex management situations can frequently arise where a depressed and acutely physically ill patient is disengaged from therapeutic intervention either due to depressive anergia, lack of motivation or nihilistic thinking in which they may feel they are beyond hope and assistance. Distinguishing patients who are gravely ill and have a realistic appreciation of their prognosis with the understandable effect on their emotional state from those patient who may be physically ill but have a distorted view of their prognosis caused by low mood can be highly challenging, and the advice of a specialist psychiatric liaison team may be helpful if uncertainty persists. In the complex setting of an emergency department, it may be extremely difficult to make this distinction without access to specialists in mental health disorders in older people.

A systematic review of the prognosis and treatment outcomes for older versus middle-aged depressed patients [19] found that in older patients, depression was equally responsive to initial treatment as depression in younger adults but that there was a more adverse long-term outcome with higher likelihood of relapse; this is probably due to medical comorbidity, emergent dementia and the larger number of previous episodes of depression in the older patients. The approach to treating depression with psychosocial interventions and medication should therefore be broadly similar in older compared with younger adults. As in many areas of therapeutics, the interpretation of evidence from treatment trials of antidepressants in older people is not straightforward owing to unresolved questions over whether the conditions in such trials (subjects’ age, general health status, treatment duration etc.) are generalisable to cases seen in everyday clinical practice. This challenge is arguably greatest for older patients as on any physiological measure, older people tend to exhibit more diversity and heterogeneity than younger adults. The most recent NICE guidance on the treatment of depression in adults acknowledged the limitation of evidence available but reinforces the importance of a stepped care model, and that to be most effective at all ages, antidepressant drug treatment needs to be embedded in a package of support and psychosocial interventions including guided self-help programmes, supervised physical activity programmes and brief focussed psychotherapies such as cognitive behavioural therapy and interpersonal therapy.

In the context of emergency geriatric care, there will be circumstances where it is opportune and clinically highly desirable to initiate antidepressant treatment during the presenting episode of acute illness rather than awaiting illness stabilisation or resolution and discharge from hospital. Moreover, as already noted in many cases, the persistence of significant depressive symptoms will have an adverse impact on the acute outcomes of the patient’s physical care and treatment making antidepressant treatment an immediate priority. Nearly all currently licensed antidepressant drugs have broadly similar efficacy, so the choice of treatment will be largely determined by consideration of the drugs’ tolerability profiles, secondary effect profiles (e.g. sedating versus non-sedating), pharmacokinetic properties and the potential for drug interactions. In most cases, this will lead to the consideration of a selective serotonin reuptake inhibitor drug as first-line treatment or alternatively a well-tolerated sedative antidepressant such as mirtazapine if this particular property is desirable. Although tricyclic and related antidepressants are initiated much less frequently nowadays in all age groups, it is not uncommon to find older patients with long-term recurrent depressive disorders who have been prescribed with these drugs for many years and are taking them at the time of presentation to hospital with an acute health problem. In addition, tricyclic drugs are very commonly used in low doses as an adjunct to pain management. The comparative properties of some of the most commonly prescribed antidepressant drugs together with selected first-generation drugs are summarised in Table 14.3.