Keywords

Introduction

There is comparatively limited data on psychiatric illness in the elderly and even less so in the oldest-old. Whilst there are broad similarities in clinical presentation and management between the oldest-old and their younger counterparts, some qualitative differences between these groups highlight the need for clinicians to modify their diagnostic and management approaches.

Psychiatry differs from most other branches of medicine in that it is based largely on the description and treatment of syndromes. Whilst research is gradually closing in on many of the biological substrates associated with psychiatric conditions, for now at least there are no definitive investigative markers with which to confirm the presence of a specific mental illness. A diagnosis of major depression or schizophrenia is based on clinical assessment, not a blood test or cerebral scan. Given the great potential for symptomatic overlap between different conditions, this can make for challenging diagnostic waters and underscores the particular importance of performing a careful history and mental state examination as part of a methodical diagnostic and management approach in this group.

Historically, distinction was made between psychological conditions that were secondary to “organic” disease (i.e. demonstrated physical conditions) and those that were primary, due to “functional or non-organic” disease (i.e. occurring in the absence of demonstrable physical illness and so assumed to have some other aetiology). This is obviously a limiting and artificial categorisation, particularly in the oldest-old where multiple physical comorbidities and polypharmacy are largely the norm and any distinction between “primary or non-organic” and “secondary or organic” becomes increasingly blurred. Nevertheless, a broad appreciation of the interplay between the “psychological” and the “physical” can still assist in diagnostic formulation and therefore in directing best initial management. This relationship could be considered as follows:

  • A physical problem (or its treatment) causes psychological symptoms.

  • A psychological problem (or its treatment) causes physical symptoms.

  • A separate condition causes both psychological and physical symptoms.

Common Psychiatric Presentations

The major neuropsychiatric syndromes encountered in the oldest-old include the mood disorders (depression and mania), anxiety disorders , psychotic disorders , and cognitive disorders (covered elsewhere in this text). On encountering these symptoms in the elderly patient, the clinician should consider whether they are:

  1. 1.

    Due to an acute, potentially reversible medical issue

  2. 2.

    Due to an acute, reversible, or transient stress

  3. 3.

    Part of a more sustained, pervasive disorder

Psychological Disturbance Due to an Acute, Potentially Reversible Medical Issue

The elderly present with underlying vulnerability in the form of age-related systemic changes, multiple medical comorbidities, and frequent polypharmacy. Even relatively minor homeostatic disturbances can result in significant psychological and behavioural symptoms. Potentially treatable causes of psychological symptoms are shown in Table 17.1.

Table 17.1 Potentially treatable causes of psychological symptoms
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Psychological Disturbance Due to an Acute, Reversible, or Transient Stress

Distinguishing these conditions from other psychiatric disorders is important, as symptom course, impact on function, and level of associated risk are different. It will also affect management; identifying these conditions does not mean no intervention is required, only that a different range of treatment approaches may be more appropriate. Common time-limited psychological reactions to intermittent stress include grief and loss, other “adjustment disorders”, to specific life stresses, and transient demoralisation, anxiety, or misperceptions in cognitive impairment and dementia [4].

Psychological Disturbance Due to a More Sustained, Pervasive Disorder

Sometimes depression, mania, anxiety, and psychosis presenting in the elderly are part of a more pervasive, entrenched constellation of symptoms that may not respond to simple general measures and require a more elaborate treatment approach. In the elderly, these may be either:

  1. 1.

    A relapse of a pre-existing condition (with its onset earlier in life)

  2. 2.

    A new condition of late onset

Pathogenesis involves a combination of underlying predisposing vulnerability factors interacting over time with any number of accumulating stresses, eventually manifesting clinically as disease. These include genetic, medical, psychological, social, and cultural influences. The extent and manner in which they combine in a particular individual can influence the way symptoms manifest.

Studies of mood and psychotic disorders in the elderly that have had their first onset earlier in life consistently show stronger associations with a positive family history. In contrast, disorders presenting for the very first time in old age have fewer genetic links. Late-onset conditions have weaker direct association with stressful psychosocial triggers and instead are more commonly associated with underlying neurological signs and medical problems, particularly cerebrovascular disease [5,6,7,8,9,10,11,12,13,14,15,16] Table 17.2.

Table 17.2 Other medical conditions associated with late-onset psychological symptoms
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Late-onset mental illness is more commonly associated with cognitive deficits. Neurocognitive assessment has demonstrated varying degrees of impaired executive function, processing speed, and attention, memory, and language function, reflecting predominantly frontosubcortical changes [23,24,25,26,27,28,29,30,31,32]. Imaging studies have shown reductions in caudate or hippocampal neuronal volume in depression and in bipolar disorder. The pathological basis remains unclear. Theories include a process of CNS neuroinflammation (associated with elevated inflammatory markers including white cells, cytokines, and CRP), reduced neurogenesis (associated with decreased brain-derived neurotrophin factor), and cumulative damage caused by repetitive stress-induced high-cortisol states [33,34,35,36,37,38,39]. Other studies emphasise the role of cerebrovascular disease in the pathogenesis of both mental illness and cognitive impairment. Certainly, cognitive changes are far more likely in the presence of underlying cerebrovascular disease, which is also associated with poorer treatment response [10,11,12, 15, 36, 40, 41]. Regardless of underlying aetiological factors, several pervasive psychiatric syndromes are commonly encountered in the elderly and are discussed below.

Major Depression

In the oldest-old, the prevalence of significant depression has been reported as ranging from around 5–32% [42,43,44]. Perhaps not surprisingly, there is a higher risk in those living alone or isolated from loved ones, those with poor physical health or impaired IADLs, and those with cognitive impairment [43, 45,46,47]. In general, depression in the very old presents in a similar fashion to other age groups. However the depressed elderly may present with less typical clinical features including higher rates of sub-threshold depressive features and “depression without sadness”, somatic preoccupation or unexplained physical symptoms, and apathy. This may affect diagnostic accuracy, particularly when using narrower definitions or excluding high-risk subpopulations (those with cognitive impairment or dwelling in residential facilities) [47,48,49,50,51,52].

Numerous attempts have been made to classify depressive subtypes. One hierarchical model proposes three broad sub-groups: non-melancholic depression (where anxiety is common, and mood disturbance is more closely linked to the underlying temperament and personality), melancholic depression (with more distinctive mood, sleep, and psychomotor changes), and psychotic depression (melancholia along with distortions in beliefs and perception that often have a mood-congruent quality) [53]. All require treatment.

Hypomania and Mania

Bipolar disorder in the elderly is uncommon, estimated at 0.1–0.5% prevalence in over 65-year-olds (compared with 1.4% in young adults) although rates are much higher in inpatient populations [54, 55]. Many cases may represent relapse of an early-onset illness, either of a previously established bipolar disorder or through a recurrent depression that has switched to mania for the first time in late life, often after a latency of some decades. New-onset cases of mood elevation have associations with the various medical, cerebrovascular, and cognitive factors described earlier. Whilst the clinical features are broadly similar at any age, mania in the elderly is arguably less intense and more likely associated with longer duration of symptoms [54]. In mania, symptoms last at least a week, cause significant functional impairment, and can be so severe that psychosis (including grandiose or paranoid delusions and marked thought disorder) occurs. At least one lifetime episode of mania enables a diagnosis of bipolar I disorder. In hypomania symptoms can be briefer (4 days) and are generally less severe (so overall function remains mostly intact). Hypomania can occur in bipolar I disorder (if mania has previously occurred) but otherwise if associated with a history of previous major depression would enable a diagnosis of bipolar II disorder [4].

Anxiety Disorders

Anxiety disorders are prevalent in the elderly at 15%, with even higher rates of less specific anxiety symptoms [56, 57]. Almost all begin earlier in life, following a relapsing-remitting course across the lifespan with a tendency to flare-up in response to life stresses (psychosocial and physical), often recurring in the elderly at the very time when long-established coping structures are starting to fail. Risk factors include female gender, being single, multiple medical comorbidities (including vascular disease), and certain temperamental traits (neuroticism and perfectionism) [58,59,60]. Only a minority will have new-onset anxiety in late life. This could be in the context of an adjustment disorder or in the setting of cognitive decline or medical illness. More prominent agitation and dysphoria would raise suspicion of anxiety secondary to a major depression, although depression and anxiety often co-exist independently in the oldest-old [61]. Common anxiety disorders include generalised anxiety disorders (GADs), phobias, panic disorder, obsessive compulsive disorder (OCD), and post-traumatic stress disorder (PTSD) [4].

In the elderly, GAD is the most common form, is highly comorbid with other psychiatric illnesses (especially depression), and is possibly more common in some medical illnesses (such as stroke or Parkinson’s disease) [61,62,63]. Phobias are also common. Specific phobias in the elderly more often involve fears around the natural environment (lightning, heights) than younger adults. They also have high rates (around 60% in some samples) of fear of falling, a multifactorial condition more frequent in the setting of balance problems or after a previous fall, which can be associated with generalised anxiety and depression [64,65,66,67,68]. Agoraphobia can be the product of fear of falling, fear of social embarrassment (e.g. in incontinence), or of having a panic attack in public. It can result in social isolation, physical deconditioning (and worsening mobility), and reduced quality of life.

Panic disorder , OCD , and PTSD are much less common and often associated with physical illness or cognitive impairment [69]. Some studies suggest more frequent obsessions around sin, more compulsive hand-washing, and more severe hoarding in older people with OCD compared to their younger counterparts [70, 71]. New traumas in late life (such as falls, cancer scares, traumatic bereavements, and frightening delirium experiences) can present with PTSD-like anxiety features, whilst physical, cognitive, and psychosocial stresses in old age can also reignite PTSD from earlier-life traumas (including childhood and military experiences).

Psychotic Disorders

Psychotic disorders are characterised by varying patterns of “positive symptoms”: distortion in beliefs (delusions), perception (illusions, hallucinations), and thought form. Delusions are strongly held convictions outside of social or cultural norms, either entirely false or unrealistic, and largely impervious to reason. There are many different forms, including persecutory, grandiose, somatic, nihilistic, and referential. Perceptual distortions in the absence (hallucinations) or presence (illusions) of an external trigger may occur in any sensory modality. Formal thought disorder, inferred through the expression of language, may be subtle (such as the divergent loss of goal in tangentiality) or prominent (such as loosening of the associated connectedness between different ideas or topics or the more dramatic loss of grammatical cohesion in “word salad”). “Negative symptoms” (flattening of affective expression, avolition, alogia, ambivalence, and reduced attention) can occur in some forms of psychosis.

Psychosis is common in old age. This is usually a secondary psychosis (as discussed earlier), although primary psychotic disorders also occur. Secondary psychotic syndromes in the elderly include delirium, dementia, and mood disorders. The primary psychotic syndromes include delusional disorder, schizophrenia, and schizoaffective disorder [4]. Whilst there is much symptomatic overlap irrespective of the underlying cause of psychosis, some patterns are often evident and hint at likely aetiology.

Primary psychotic illnesses with their onset early in life follow a variable course and can persist into old age. Depending on the severity of the illness and the efficacy of previous treatment, one may expect to see the psychosocial impacts of many decades of a chronic or relapsing-remitting illness. The toll of many years of antipsychotic dopaminergic blockade or mood stabiliser use will also often be evident in the form of extrapyramidal side effects, tardive syndromes, metabolic disease, or renal and electrolyte abnormality.

Primary psychotic conditions can also have their onset in late life. There is a clear female preponderance. Higher rates have been reported in populations who experience marginalisation, discrimination, or communication difficulties such as migrants and the hearing or vision impaired. Clinically they may meet traditional criteria for schizophrenia or delusional disorder, or fall somewhere in between. They have been variously referred to as late paraphrenia, late-onset (after age 40) schizophrenia, and very late-onset (after age 60) schizophrenia-like psychosis, reflecting the lack of clarity in definition, classification, and phenomenology in the literature, in what is likely a very heterogeneous group of patients [72, 73]. Persecutory beliefs occur in the majority, often in the form of “partition delusions” (the belief of being monitored or affected by someone through the walls, floor or ceiling, either directly or with gas, radiation, or electricity). Auditory hallucinations are common. Disorder of thought form is rare and affect is usually preserved. Mild cognitive deficit may be evident [32, 74,75,76].

Suicide in the Elderly

Suicide is significantly more common in males, with two peaks across the lifespan: one in middle age and a second in the oldest-old. Australian rates in 2015 were 31.5/100,000 men aged 45–49 and 39.3/100,000 men over 85 [77]. Depression is a prominent risk factor, especially when anxiety is comorbid, yet in a concerning majority of cases, it will remain undetected prior to the attempt [78,79,80,81]. Higher rates are reported in the presence of physical illness (especially cancer and cardiovascular disease) or disability, in social isolation, and in temperaments characterised by introversion, anxious, and obsessional features [78, 79, 82,83,84]. A disrupted sense of self following traumatic loss, loneliness, intolerable anxiety, loss of control or autonomy, and hopelessness have been described as common underlying themes [84,85,86].

Key Elements of the Psychiatric Assessment in the Elderly

History and Examination

  1. 1.

    Obtain collateral information (from family, friends, caregivers) especially in the presence of cognitive impairment, where recollection and articulation of symptoms can become limited. In addition to aiding diagnosis, this provides valuable information regarding premorbid personality style, baseline function, and extent of existing social and supportive structures.

  2. 2.

    Explore risk in all its forms:

    • Risk to self (through deliberate self-harm, misadventure, self-neglect)

    • Risk to reputation or financial security

    • Risk from others (through neglect or deliberate abuse)

    • Risk to others (through aggression or negligence)

    The nature and extent of risk will strongly influence choice of treatment setting.

  3. 3.

    Clarify whether this is the first presentation of psychological illness or relapse of a longstanding recurrent illness. Look for underlying triggers and risk factors (including family history, underlying cerebrovascular risk factors, a history of relevant medical conditions, or use of medications commonly associated with mental disturbance).

  4. 4.

    Be mindful of the high prevalence of sub-syndromal or somatic presentations of depression and anxiety in this age group.

  5. 5.

    Always ask about substance use. Misuse or abuse of alcohol or prescription medications (especially benzodiazepines and opiates) or excessive caffeine intake is easily overlooked.

  6. 6.

    Always perform a bedside cognitive assessment.

Medical Investigation

Whilst there is no standardised approach to selection of investigations, a reasonable initial “aged care psychiatry screen” would include (Table 17.3).

Table 17.3 Initial investigative screen
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The use of reliable, valid rating scales is no substitute for careful clinical assessment but may add weight to diagnostic impressions. The Geriatric Depression Scale is a commonly used self-rating 30-item questionnaire that is quick and simple to administer; a shorter 15-item version may be preferable in the presence of fatigue or mild cognitive impairment. In dementia, the Cornell Scale for Depression in Dementia, which combines patient and carer interviews, is preferred and also has validity in patients without dementia [91,92,93].

Treatment

The burden of untreated mental illness, at any age, is readily apparent. The anguish of “psychological pain” is as profound as physical pain. It impacts on self-confidence, identity, relationships, and function; active mental illness impairs our ability to maintain meaningful connections with who we are, what we do, and who we do it with.

There are also hidden risks of untreated illness. Depression is an established independent risk factor for coronary heart disease, impacts on recovery and increases adverse outcomes following heart attack. It has been shown to increase risk of stroke. Similar evidence is growing for anxiety disorders. Mental illness generally carries increased mortality risk via medical illness and suicide [78, 94,95,96]. Therapy aims to reduce suffering and disability, improve quality of life, and where possible reduce morbidity and mortality.

General Treatment Approaches

Treatment of any acute medical issues identified during the initial physical assessment should occur, along with rationalisation of any polypharmacy (and where possible tapering of agents detrimental to mental state). Given the interaction between psychological distress, psychosocial risk factors, and physical problems in the oldest-old, there are several initial broad management approaches that have relevance regardless of the presenting flavour of mental disturbance and can be promoted by any clinician Box 17.1.

Box 17.1 General Treatment Measures

Supportive contact

Facilitating access to practical supports such as transport and assistance around the home, and supportive interaction with an empathic clinician.

Regular exercise

Aerobic exercise has shown benefits in both prevention and treatment of depression. It has positive effects in anxiety and can help improve sleep [97,98,99]. Both aerobic and anabolic exercise have been shown to increase cortical volume and improve memory and executive function in mild cognitive impairment [100,101,102].

Sunlight and sleep hygiene

Dysregulation of circadian rhythms can have significant impacts on sleep and mental well-being. A dose of direct morning sunlight soon after waking can be beneficial, along with broader healthy sleep hygiene habits [97, 103].

Manage substance use

The negative impacts (psychologically and physically) of alcohol and benzodiazepines should be addressed. Nicotine and caffeine can aggravate anxiety and impair quality of sleep.

Healthy diet

Encouraging good hydration and a healthy balanced diet is important in brain health. Regular intake of omega-3 fatty acids can be beneficial in cerebrovascular health and in depression. Folate has shown benefits in augmentation of antidepressants [90, 104, 105].

Socialisation and diversional activity

Encourage regular engagement in pleasurable diversional activities across the week, alone and in company, in and out of the home.

Education and “self-help” resources

Psychoeducation helps empower individuals, is a fundamental element of informed consent, and facilitates collaborative management.

Information sources: Nagas et al. [90]; Malhi et al. [97]; Ensai et al. [98]; Schuch et al. [99];Suo et al. [100]; Fiatarone et al. [101]; Colcombe et al. [102]; Wirz-Justice et al. [103]; Lin et al. [104]; Opie et al. [105].

Focused Approaches: Psychological/Behavioural Therapies

In combination with general treatment approaches, non-pharmacological strategies may be all that is required for some types of disorder. They can be delivered individually or in a group setting. One of the more rigorously studied interventions is cognitive behavioural therapy (CBT), which comprises a wide array of psychological and behavioural strategies delivered in a systematic and structured manner, aiming to modify unhelpful patterns of thinking or action that may be contributing to ongoing symptoms or distress, with a focus on “here and now” issues. There is a considerable body of evidence for efficacy of CBT in insomnia, chronic pain, substance use, depression, delusions, and hallucinations in some psychoses, and it is particularly effective in anxiety disorders (often as stand-alone treatment), although limited data exists for the oldest-old [106, 107]. Success in therapy requires a degree of motivation and commitment to the process.

Focused Approaches: Biological Therapies

Biological treatment options include medication and neurostimulation and are generally similar to other age groups. Despite the inherent risks of adverse effects, rates of antidepressant, antipsychotic, and sedative prescription are significantly higher in the oldest-old than any other group, particularly in aged care residential settings [108]. As always, obtaining informed consent should be the first step.

Depression

Antidepressants are indicated in moderate-severe depression, when they are often combined with CBT. Generally, different antidepressant classes have shown comparable efficacy (around 50–60%) in most studies, and choice of agent will be influenced more by tolerability, although some studies have suggested superior efficacy for venlafaxine or tricyclic antidepressants over SSRIs. Some studies suggest less benefit for late-onset depression in the setting of vascular disease and in dementia [23, 97, 109, 110].

SSRIs (selective serotonin reuptake inhibitors) are a reasonable first-line choice. Early side effects usually settle within 1–2 weeks. Alternatives would include SNRIs (serotonin and noradrenaline reuptake inhibitors, particularly if depression is more severe or if there is comorbid neuropathic pain), NaSSA (noradrenaline and specific serotonin antidepressant), agomelatine, or NARI (noradrenaline reuptake inhibitor) (Tables 17.4 and 17.5).

Table 17.4 SSRIs
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Table 17.5 Other first-line antidepressant options
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Whilst early benefits may be seen within a few weeks, onset can be considerably delayed (10–12 weeks) in the elderly; it is important to resist the temptation to change treatment too early and instead allow an adequate therapeutic trial. If intolerable or ineffective, options would include changing dose or changing antidepressant class. Thereafter, options would include a switch in class to a second- or third-line antidepressant or augmentation with a different agent (lithium, atypical antipsychotics, thyroxine) [97] [Table 17.6].

Table 17.6 Second-line antidepressants
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In major depression with psychosis, an antipsychotic will often be added to the antidepressant early in treatment. In bipolar depression, antidepressants can induce a mood swing into mania or rapid mood cycling. Initial monotherapy with a mood stabiliser (lithium, valproate, lamotrigine) or second-generation antipsychotic may suffice; alternatively an antidepressant may be used in combination with a mood stabiliser [97].

All antidepressants (but especially SSRI/SNRI) can cause hyponatraemia. Serotonergic antidepressants have the potential to cause serotonin syndrome, especially if combined with other serotonergic agents.

Neurostimulation therapy is an ever-developing field. Electroconvulsive therapy is a well-established antidepressant treatment superior to medication, with remission rates of around 60–90% [113,114,115]. Whilst often used in cases of medication intolerance or inadequacy, it can be used as first line for its more rapid onset of effect if there are acute risks (active suicidality or poor oral intake) or in melancholic and psychotic subtypes where it is particularly effective. It also has demonstrated benefits in the treatment of mania, schizophrenia, and several neurological conditions (catatonia, Parkinson’s disease, neuroleptic malignant syndrome). As long as the patient can tolerate a general anaesthetic and the cardiovascular effects of treatment (rapid changes in heart rate and blood pressure) and has no relative contraindications (very recent MI or CVA, raised intracranial pressure or space-occupying lesion, retinal detachment), the treatment can be used safely in the oldest-old, where response rates are similar but relapse rates high [115, 116]. Side effects are usually minor (headache, nausea); however, the main concern is the potential for cognitive problems (acute confusion, anterograde and retrograde memory problems, executive dysfunction); in the vast majority these are time-limited and resolve once clear of the treatment course; however, some will experience persisting deficits into the longer term. Whilst ECT remains unsurpassed in terms of efficacy in depression, other emerging promising neurostimulation modalities include transcranial magnetic stimulation (TMS), which has the advantage of no anaesthetic or cognitive impacts.

Mania

Medications used to treat mania comprise a diverse collection of agents from different pharmacological groups (Table 17.7).

Table 17.7 First-line anti-manic medications
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In mania, any medication that could be contributing to mood elevation should be weaned and an anti-manic agent commenced. If ineffective, options include a switch in agent, trial of second-line treatments (such as carbamazepine), or use of combinations. ECT can also be effective and should be used early if symptoms are severe [97].

Anxiety

Antidepressants have efficacy in anxiety disorders. SSRIs or SNRIs may be used as first line and often augment psychological approaches [58]. Anxious patients are often somatically hypervigilant and can misattribute symptoms of anxiety to medication side effects; careful explanation can often prevent premature abandonment of treatment or unnecessary multiple trials. In some cases, addition of other anxiolytics in low dose (including atypical antipsychotics and pregabalin) early in the course of treatment may help control some symptoms of arousal until the antidepressant agent has achieved response [117, 118]. Benzodiazepines should be avoided if possible or used in low doses for brief periods only.

Psychosis

In the elderly, antipsychotics carry a considerable risk of side effect burden. As always, this risk needs to be weighed against the risk of untreated symptoms and the likelihood the antipsychotic will improve things. In dementia, non-pharmacological options should always be the primary therapeutic focus, with antipsychotic medication reserved for more persistent psychotic symptoms associated with distress, problematic behaviours, or elevated risk. Late-onset schizophrenia tends to respond to much smaller antipsychotic doses than early-onset forms [73, 119, 120].

Atypical (second-generation) antipsychotics are generally preferred for their more tolerable side effect profile. Nevertheless, they also carry risk of adverse effects (Table 17.8). Furthermore studies have shown in some populations (dementia) an increased risk of mortality (especially through pneumonia and cardiac problems) and morbidity (including cerebrovascular disease) [119]. Apart from clozapine (rarely used in the elderly), quetiapine has the least potential for EPSE. Aripiprazole has fewer metabolic side effects, and risperidone has fewer anticholinergic side effects (Table 17.8). Whilst oral preparations are preferable, in cases of poor compliance, injectable depot administration may be utilised.

Table 17.8 Side effects of antipsychotic medications
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Clinical Relevance

  • Mental illness in the elderly can be due to relapse of early-onset disease or a new late-onset process.

  • Medical causes of psychological disease in the oldest-old are very common. Identification and treatment is always the first priority.

  • Depression in the elderly commonly presents with somatic or sub-syndromal features.

  • Whilst treatment approaches are similar to younger populations, medication should be introduced slowly in low doses.

  • Antidepressants and antipsychotics carry a significant side effect burden, and their potential benefit must outweigh this risk.

  • Electroconvulsive therapy is most effective for melancholic or psychotic depression subtypes and can be safely used in the elderly.

  • In dementia, non-pharmacological strategies for behavioural and psychological symptoms are first line.

  • Elderly males have the highest suicide rates. Exploring suicide and other risks is an essential part of the basic assessment.