Depression in Older Adults

Background

• Major depressive disorder (MDD) has a heterogeneous clinical presentation such that 2 patients with the diagnosis may have only a few symptoms in common.
• The prevalence of major depressive disorder is reported to be ≥ 5% in community-dwelling older adults, and clinically significant depressive symptoms may be present in 8%-16% of older adults.
• Some patients have specific subtypes of depression, which may be clinically useful for predicting outcomes and choosing treatment. They include:
  • melancholic depression (melancholia)
  • depression with atypical features
  • MDD with psychotic features
  • MDD with catatonia
  • MDD with anxious distress
• MDD classification by episode (first or recurrent), status (such as partial or full remission) and severity is relevant to treatment. Severity classifications include:
  • mild MDD - the minimum number of symptoms present, symptoms are distressing but manageable, and minor functional impairment
  • moderate MDD - falls between mild and severe
  • severe MDD - substantial excess of required symptoms present, symptoms are unmanageable for patient, and disability in responsibilities is apparent
• Risk factors for depression commonly seen in older patients include recent losses, social isolation, stroke, and chronic medical problems such as orthopedic pain.
• The prognosis for untreated MDD is poor in older adults, and much better with treatment. The course is variable with about 15% of patients experiencing unremitting depression and 35% experiencing recurrence. Older adults have a similar rate of remission to younger adults but are at increased risk for recurrence.
• Screen high-risk patients or patients with suspected depression with a standardized instrument such as the Patient Health Questionnaire-9 (PHQ-9) or the Geriatric Depression Scale.
• Identify and promptly treat or refer patients who exhibit suicidal ideation.

Evaluation

• Depression is a clinical diagnosis based on the presence of a depressed mood or anhedonia and associated symptoms, usually defined by either Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5) or ICD-10 criteria with the exclusion of other causes.
• Symptoms include:
  • significant change in weight or appetite
  • insomnia or hypersomnia
  • psychomotor agitation or retardation nearly every day (observable by others)
  • fatigue or loss of energy
  • feelings of worthlessness or excessive or inappropriate guilt
  • indecisiveness or decreased ability to concentrate
  • recurrent thoughts of death or suicide
• Depression generally presents similarly in older adults and younger adults but may be underrecognized in older adults due to misattribution to aging, dementia, or medical illness. Vegetative signs and cognitive disturbances are more common in older adults who may be less likely to report dysphoria than younger adults.
• Perform cognitive assessment in all older adults with depressive symptoms, as depression is often associated with cognitive impairment in this population and syndromes of dementia may mimic or be associated with depression.
• Important differential diagnoses to consider include other mood disorders, especially bipolar disorder, psychotic disorders, substance abuse, and medical conditions such as hypothyroidism and Cushing disease. Consider checking thyroid stimulating hormone in women ≥ 65 years old with suspected depression.
• Identification of co-occurring medical conditions is essential in older patients, as they may cause or mimic depression, or affect choice and/or dosing of medications (Strong recommendation). Medical conditions which may cause or mimic depression include:
  • dementia
  • delirium
  • hypothyroidism
  • Parkinson disease
  • stroke
  • connective tissue diseases
  • substance use
• Careful and ongoing evaluation of suicide risk is necessary for all patients with suspected or diagnosed major depressive disorder (Strong recommendation).

Management

• Hospitalization or immediate specialist consultation is usually needed for patients who pose a serious threat of harm to self or others (Strong recommendation) and should be considered for those that are severely depressed, especially if they lack social supports or have complicating medical or psychiatric conditions.
• Treatment in older patients should parallel treatment of depression in the general population other than special considerations for medication interactions, dosing, and side effects.
• Classes of antidepressants appear equally effective for achieving remission and response in older adults with depression.
• Recommended initial treatment choices for mild-to-moderate depression:
  • American Psychiatric Association (APA) considers antidepressants an initial treatment choice while National Institute for Health and Care Excellence (NICE) in United Kingdom recommends an antidepressant only if the patient is unresponsive to psychosocial intervention.
  • Psychotherapy as an initial treatment of choice is recommended (Strong recommendation).
  • Psychotherapy plus an antidepressant should be used if there are comorbid psychosocial problems.
• Recommended initial treatment choices for moderate-to-severe depression:
  • Combination antidepressant plus psychotherapy is recommended (Strong recommendation).
  • Electroconvulsive therapy (ECT) is recommended for severe unresponsive major depression or when there is an urgent need for response (Strong recommendation).
• Antidepressants (selective serotonin reuptake inhibitors [SSRIs], serotonin norepinephrine reuptake inhibitors [SNRIs], atypicals, tricyclic antidepressants [TCAs], and monoamine oxidase inhibitors [MAOIs]) appear effective for reducing symptoms and increasing remission in older adults with depression or dysthymia.
• After achieving remission, continuation of therapy should last 4-9 months.
  • Additional maintenance therapy after the continuation period should be considered for patients with risk factors for relapse or recurrence or who have already experienced recurrent episodes of depression (Strong recommendation).
• About 67% of older adults do not achieve remission with initial antidepressants therapy and require further interventions such as another antidepressant (associated with 50% response rate), psychosocial intervention, or electroconvulsive therapy.
• Special considerations for pharmacological management of depression in older adults include:
  • Consider medications with efficacy for several conditions to reduce the number of prescriptions.
  • Elderly patients may require lower oral doses and may have lower tolerance than younger patients.
  • Adjust dose regimens for age-specific metabolic changes and carefully monitor hepatic and renal metabolic function.
  • Carefully monitor potential drug interactions.
    • Fluoxetine, fluvoxamine, and paroxetine are associated with higher risk for drug interactions than other SSRIs.
  • In older patients more prone to orthostatic hypotension and cholinergic blockade - consider SSRIs, serotonin-norepinephrine reuptake inhibitors (SNRIs) and other antidepressants before TCAs or MAOIs.
  • Carefully monitor for side effects:
    • SSRIs may cause hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) at higher rate in older patients.
    • Antidepressant medication is associated with increased incidence of falls, fractures, and dizziness in older adults.
    • SNRI and TCA antidepressants may be more appropriate than SSRIs for patients with melancholic depression.
  • Antidepressants may not be effective in the treatment of depression in patients with dementia.