Depressive disorders are common and disabling, particularly among older people who live in residential aged care or who have a comorbid illness.135 Prevalence estimates vary depending on the methodology used and the definition of depression.136 An Australian survey estimated that 51% of high care residents and 30% of low care residents without cognitive impairment had major depression based on the Geriatric Depression Scale.137
Depression in residents has been associated with recent bereavement, physical illness, cultural factors, quality of the home environment, existence of depression before admission, and the ways in which depression is treated.138
Depressive disorders include major and minor depression. Diagnostic criteria for major depression are shown in Table 8. Residents with minor depression (depressive symptoms without fulfilling DSM-IV criteria for major depression) may be just as distressed and functionally disabled by their symptoms as those with major depression.139
Table 8. DSM-IV criteria for major depression 140
DSM-IV criteria for major depression are five or more of the following symptoms persisting over a 2 week period causing clinically important distress or impairing work, social or personal functioning (with depressed mood or decreased interest or pleasure as one of the five):
- Depressed mood most of the day, occurring most days(subjective or observed)
- Markedly diminished interest or pleasure most of the day, nearly every day
- Significant weight or appetite change
- Insomnia or hypersomnia
- Psychomotor agitation or retardation (observable by others)
- Fatigue or loss of energy
- Feelings of worthlessness or inappropriate guilt
- Diminished ability to concentrate or make decisions
- Recurring thoughts of death or suicide plans
Older people may have a recurrence of early onset depressive symptoms, or present with depression for the first time later in life (over 50 years of age). Early onset depressive disorders are likely to be associated with genetic risk and cognitive vulnerability to depression, and have an increased risk of developing coronary and cerebrovascular disease. Late onset depressive disorders are often associated with pre-existing physical illness, particularly cerebrovascular disease (eg. vascular depression and poststroke depression), heart disease, diabetes, cancer, Parkinson disease, dementia and cognitive impairment.141, 142 Depression may also occur in residents receiving palliative care.143
Vascular depression is characterised by a lack of family history of depression, subcortical neurological dysfunction, cognitive impairment and psychomotor change. Patients with vascular depression may later develop vascular dementia.144
Poststroke depression develops over months, with peak prevalence between 3-24 months, and is associated with poor functional and psychosocial outcome. Predictive factors are aphasia 3-12 months after stroke, older age, limited social supports and a previous history of psychiatric problems. It usually remits after 1-2 years, but some cases persist up to 3 years following stroke.145
Depression in residents may be unrecognised and untreated as older people may not report symptoms or may attribute symptoms to ageing or physical causes. Also, symptoms are more likely to be somatic or atypical.
Assessment involves obtaining a history from residents and their relatives, the use of depression assessment scales and cognitive testing, physical examination, and investigations. The purpose of assessment is to:
- confirm diagnosis and the severity of depression
- differentiate depression from dementia and delirium
- identify reversible causes
- identify other conditions that may contribute to depression or be aggravated by depression assess the risk of self harm.
Clinical features of depression in older patients include:146
- psychological-fluctuating depressed mood, loss of interest in activities, loss of motivation, irritability
- somatic-loss of energy, fatigue, headache, pain and palpitations
- cognitive-forgetfulness, poor concentration, psychomotor slowing
- behavioural-social withdrawal, reduction in activity, disinhibition.
Patients with severe depression may also exhibit cognitive dysfunction, psychotic symptoms and melancholia. Symptoms of depression may be due to an underlying medical condition or cognitive impairment rather than an underlying mood disorder. Differential diagnoses include dementia, delirium, side effects of medications, sepsis and hypothermia.147
Table 6 (see Dementia) compares the clinical features of depression with dementia and delirium. Cognitive testing (eg. using the MMSE) can help differentiate between dementia and depression. There are several depression assessment tests available that have been validated in older populations. The Geriatric Depression Scale (see Tool 5) and the Cornell Scale for Depression in Dementia (see Tool 6) are recommended.148 The Geriatric Depression Scale is suitable for detecting major depression in older people without dementia. The Cornell Scale is designed for the assessment of depression in older people with dementia who can at least communicate basic needs. The Beck Depression Scale is recommended for patients poststroke, as it has low reliance on somatic symptoms and memory.149
Review medications to identify those with potential depressive effects(eg. anticonvulsants,acitretin, corticosteroids or progesterone). Investigations can help identify reversible causes of depression including vitamin B12 deficiency, hypothyroidism, delirium or sepsis.150 Look for conditions that could contribute to depression or affect treatment (eg. chronic insomnia, pain, incontinence, alcoholism, stroke, recent myocardial infarction, dementia, Parkinson disease). Neurological imaging may help assess dementia and cerebrovascular disease. Assess whether the patient is at risk of self harm (eg. by using the guide to assessment of suicide risk in the Psychotropic therapeutic guidelines).151
Most older patients with depression will respond to treatment, with improvement in function and wellbeing. Overall, the prognosis for late onset depression is similar to that for younger patients.152
Treatment of depressive symptoms involves a combination of nonmedication therapies (eg. patient education, behavioural strategies, psychotherapy) and antidepressant medication.
Management also includes the treatment of reversible causes, change in medications or situations that are contributing to the depression, adequate treatment of associated medical conditions, and reduction of self harm risk.
Monitor progress regularly, and consider specialist referral for patients:153
- with severe, melancholic or psychotic depression
- who fail to respond to treatment
- who are at significant risk of self harm
- where the diagnosis is unclear
- where specialist treatments are required, eg. electroconvulsive therapy.
Psychosocial management is the main treatment for mild depression related to loss, and provides additional support to antidepressant medication in major depression (eg. poststroke). Psychosocial management includes patient and family education, counselling, cognitive behavioural therapy, interpersonal therapy, re-establishment of sleep pattern, addressing functional difficulties, increasing social participation, diet, and regular exercise.154 Exercise is effective in relieving symptoms in mild to moderate depression, improving mobility, and reducing risks for vascular disease and falls. Exercise can involve a daily walk or resistance training.155
Antidepressants are effective in treating major depression, however there is limited evidence for their effectiveness in minor depression.156 Clinical trials demonstrate similar efficacy across the major medication classes of antidepressants for major depression. Combinations have not been shown to be more effective than monotherapy, and have a significant risk of serious adverse effects. When choosing medications, consider the patient`s history and previous response to antidepressants, adverse effect profiles, and the potential for medication interactions with current medications.157 Refer to guidelines for details of antidepressants, dosage regimens, adverse effects, interactions and discontinuation.158
The selective serotonin reuptake inhibitors (SSRIs) are first line antidepressants in the elderly as they have a safe side effect profile, a relatively quick onset of action of 7-10 days, and good anti-anxiolytic effects. Maximum benefit may take 6 weeks and treatment should be continued for at least 6 months. Most patients who have a relapse will respond to reinstated treatment. Monitor regularly for benefits and adverse effects, including falls and common effects of specific classes of medications.159 Adjunctive therapies with antipsychotics and electroconvulsive therapy are sometimes indicated for patients with severe depression.