Late-life Depression (Geriatric Depression)

Geriatric Depression (also known as Late-Life Depression, or LLD) is a subtype of depression characterized by changes in mood, lack of pleasure, and often somatic symptoms in older adults. It is one of the major geriatric giants. It is most commonly defined as depression occurring in adults age 60 and over.^[1]

• The community prevalence rates of late-life depression is 11.2% for combined symptoms of major and minor depression.^[2]

• Compared to individuals with an earlier age-of-onset of depression, late-onset depression has a worse prognosis, a more chronic course, and generally a higher relapse rate.^[3]
• There is thought to be an association between vascular disease and depression, and that depression in late-life is a prodrome (warning sign) for neurodegenerative disorders.

• Late-life depression is complicated by higher rates of medical comorbidity, cognitive impairment, and mortality.^[4]

• Medical comorbidity, cardiovascular disease, low education, and increased age are risk factors.^[5]

• Generally, the diagnosis of late life depression can be made using DSM 5 criteria for major depressive disorder.
  • However, older adults are less likely to directly endorse being “depressed”, guilt, or hopelessness
  • More commonly, individuals will endorse anhedonia, cognitive concerns (poor concentration, memory, and decision-making capacity), and somatic complaints.^[6]
• Awareness of other medical causes and psychosocial causes must be thoroughly considered due to higher rates of medical comorbidities.
  • For example, the criterion for “markedly diminished interest or pleasure” may overlap with or be confused with the apathy due to dementia or an underlying neurological disease.
  • Psychomotor slowing, sleep changes, fatigue, low energy, weight loss and/or poor appetite can also be caused by an underlying medical illness, major neurocognitive disorder, substances (such as alcohol or opioids).
  • Feelings of worthlessness and suicidal ideation can also be due to end-of-life issues rather than a depressive episode.^[7]

A complete assessment for late-life depression requires:

• Reviewing the diagnostic criteria for late-life depression
• Reviewing current medications, allergies, and substance use
• Reviewing current stresses and life situation
• Assessing level of functioning/disability
• Considering support system, family situation, and personal strengths
• Cognitive testing
• Neurological exam and physical exam if applicable
• Ordering laboratory investigations to identify any medical problems that could contribute to or mimic depressive symptoms (e.g. - hypothyroidism, anemia)

• Older adults have one of the highest suicide rates in North America, largely due to the risk in older white males (higher intent and likelihood to complete suicide).^[8]

• The vascular depression hypothesis suggests that cerebrovascular disease predisposes, precipitates, or perpetuates depressive symptoms in late-life. Vascular disease (e.g. - atherosclerosis, strokes, white matter disease) are thought to affect fronto-striatal circuitry, resulting in executive dysfunction, depression, and cognitive impairment.^[9]

• Antidepressants do not work well in the treatment of depression in individuals with dementia.^[14][15]
  • Rigorous randomized clinical trials have not shown benefit (mirtazapine, sertraline) over placebo.^[16]
  • Therefore, guidelines do not suggest the routine treatment of depression and anxiety with antidepressants.

• Routine investigations should be done including: CBC, electrolytes, extended electrolytes (calcium, magnesium, phosphate), TSH, and vitamin B12

• Depression, dementia, and cognitive impairment are often associated with vitamin B12 (cobalamin) deficiency and folate deficiency, especially in the elderly. Although laboratory norms and ranges may show that a serum vitamin B12 level between 200 pg/mL and 900 pg/mL is considered normal, a minimum level of 300 to 350 pg/mL is desirable in the elderly.^[17]

• A neurological exam is recommended if there are symptoms such as tremors or falls.

• Cognitive behavioural therapy (CBT), problem-solving treatment (PST), and interpersonal therapy (IPT) has strong evidence in late-life depression.^[18]

• Bupropion, mirtazapine, moclobemide, and venlafaxine are all relatively safe in the elderly. They have lower anticholinergic effects compared to older antidepressants like tricyclic antidepressants. This also makes them relatively well-tolerated by patients with cardiovascular disease.
• There have been paradoxical findings in antidepressants studies in late-life depression, showing that commonly prescribed medications such as escitalopram and citalopram do not outperform placebo (while more anticholinergic medication such as paroxetine did).^[19]
  • One reason for these findings is that depression in the elderly is best conceptualized as a heterogenous syndrome, representing “true biological depression”, and other mimics, such as early signs of dementia or vascular depression.
  • Many clinicians opt to prescribe medications with lower anticholinergic burden to minimize delirium and cognitive impairment risk. Other considerations include medications with a lower risk for falls.
• Generally speaking however, in clinical studies, tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOis) have been shown to be the most efficacious in the treatment of geriatric depression.^[20]
  • Thus, if tricyclic antidepressants (TCAs) need to be used, nortriptyline and desipramine have the lowest anticholinergic burden, and are the most tolerated of the TCAs.^[21]
• Lithium augmentation for treatment-refractory depression also has evidence.^[22]

• ECT is a safe and effective treatment for depression in older adults.
• Older adults who receive ECT have a lower mortality rate compared to other depression treatments (i.e. - antidepressants)^[26][27]
• Right unilateral, ultrabrief pulse ECT (average of 7 treatments of ECT), when combined with venlafaxine, can be a rapidly acting and effective treatment in depressed geriatric patients. There very good safety and tolerability when this combination therapy is used.^[28]