Describe the prevalence, clinical presentation and management of depression in the elderly. What is the role of ECT in an elderly patient with depression?

Prevalence. Major depression affects 1–5% of community-dwelling elderly, but clinically relevant depressive symptoms occur in 8–16%. Rates rise with setting: 5–10% in primary care, 10–20% of medical inpatients, and highest in long-term care. In India, LASI Wave-1 reported major depression in about 8% of those aged 60 and above. It is the commonest psychiatric disorder in old age, yet remains under-diagnosed and under-treated.

Risk factors. Female sex, widowhood and loneliness, physical illness and disability, chronic pain, cognitive impairment, previous depression, family history, low socioeconomic status, caregiving, and drug-induced depression — steroids, beta-blockers, levodopa, and 5-alpha reductase inhibitors (finasteride, dutasteride), which are linked to depression and suicidality.

DSM-5 classification. Major depressive disorder = depressed mood and/or loss of interest for ≥2 weeks plus a total of ≥5 of 9 symptoms (worthlessness/guilt, poor concentration, fatigue, psychomotor change, insomnia/hypersomnia, appetite or weight change, recurrent thoughts of death). Dysthymia is now "persistent depressive disorder" (≥2 years); the "with anxious distress" specifier was added and the bereavement exclusion removed — both especially relevant to older people.

Atypical clinical presentation — the exam favourite. Older people present with somatic complaints and hypochondriacal preoccupation rather than sadness; "depression without sadness" is common. Expect psychomotor retardation or agitation, nihilistic delusions, anxiety, irritability, weight loss and insomnia, non-adherence to medical treatment, and cognitive complaints.

Important subtypes. Psychotic depression — nihilistic and guilt delusions, higher suicide risk, needs antidepressant plus antipsychotic, or ECT. Melancholic depression with psychomotor symptoms — predicts response to TCAs, dopaminergic antidepressants and ECT. "Vascular depression", now termed ischaemic subcortical depression or depression–executive dysfunction syndrome — late onset, apathy, impaired insight, executive dysfunction, deep white-matter hyperintensities; its clinical validity is now regarded as limited.

Differential diagnosis. Dementia (depressive pseudodementia versus true dementia), delirium, apathy syndrome — distinguished by the absence of dysphoria and absence of neurovegetative symptoms — hypothyroidism, B12 deficiency, occult malignancy, Parkinson's disease, and normal grief.

Assessment and workup. History plus informant history; GDS-15 (or the Cornell Scale if dementia is present); MMSE/MoCA; physical examination with attention to vascular risk factors, weight, mobility, balance and ADLs. Investigations: CBC, sodium and potassium (mEq/L), calcium (mg/dL), glucose (mg/dL), liver function, TSH, vitamin B12 and folate, with an ECG before a TCA. Always ask directly about suicidal ideation — asking does not increase risk and most patients are relieved.

Non-pharmacological management. Watchful waiting is appropriate for mild depression, since many improve spontaneously. Psychotherapy is helpful in mild-to-moderate depression and is as effective in older as in younger adults — CBT, problem-solving therapy (best where executive dysfunction is present), interpersonal therapy, reminiscence and life review. Exercise is effective in depressive disorder, minor depression and subthreshold symptoms. Add psychoeducation with family and multidisciplinary outpatient team care.

Pharmacological management. Antidepressants are just as effective in older people as in younger adults. SSRIs are first-line (sertraline, escitalopram); SNRIs and mirtazapine are alternatives; start at half the adult dose and titrate slowly; allow 6–12 weeks for full response. On non-response to an SSRI, switch antidepressant or add lithium; after TCA failure, lithium augmentation is probably the best option. Continue for at least 1 year after a first recurrence; consider lifelong maintenance after a second or subsequent recurrence.

Prognosis and impact. The course is more chronic than in younger adults; among those without significant comorbidity or dementia who are optimally treated, over 80% recover and remain well. Mortality is increased — mainly cardiovascular and, to a lesser extent, suicide — and both severity and duration of symptoms predict mortality, especially where loneliness coexists. Depression impairs well-being and daily functioning more than diabetes, heart disease or lung disease.

OPTIMUM trial (Lenze et al., NEJM, March 2023). In adults over 60 with treatment-resistant depression, augmentation of the existing antidepressant with aripiprazole improved psychological well-being more than switching to bupropion — remission approximately 28% for aripiprazole and bupropion augmentation versus 19% for a switch to bupropion — with a lower fall risk than the bupropion arm. Step 2 showed lithium augmentation and a switch to nortriptyline were similarly modest. Aripiprazole augmentation is therefore now the evidence-based next step in late-life treatment-resistant depression.

ECT versus ketamine (ELEKT-D, NEJM 2023) and modern ECT technique. In treatment-resistant depression without psychosis, subanaesthetic intravenous ketamine was non-inferior to ECT, offering an alternative where ECT is refused or unavailable — but ECT remains superior in psychotic depression, catatonia and acute suicidality, all of which were excluded from that trial. Current practice favours right unilateral ultrabrief-pulse ECT, which gives comparable efficacy with substantially less cognitive impairment in older adults.