Description

A primary mood disorder characterized by a depressed mood and/or a markedly decreased interest or pleasure in normally enjoyable activities most of the day, almost every day for at least 2 weeks, and causing significant distress or impairment in daily functioning. The geriatric population can have variable presentations and comorbid conditions that present different challenges than treating depression in the younger population.

Epidemiology

Incidence

• 2–10% of community-dwelling elderly
• 5–10% seen in primary care clinics
• 10–37% of hospitalized elderly patients
• 12–27% of nursing home residents

Prevalence

• The Global Burden of Disease Study (2015) estimated the prevalence of depressive disorders among older adults (>60 years old) of 4–6% among males and 5–8% among females.
• Suicide is the 11th leading cause of death in the United States for all ages. The elderly account for 24% of all completed suicides with the highest rates for males aged >85 years.

Etiology and Pathophysiology

• A complex interaction between heritable, biologic, psychological, and environmental factors
• Abnormalities in neurotrophins, neurogenesis, neuroimmune systems, and neuroendocrine systems

Genetics
Possible mechanisms, including genetic influences on monoamine transmission and associated transcriptional and translational activity and dysregulation in biologic processes and proteostasis involving C-peptide, FABP-liver, and ApoA-IV proteins

Risk Factors

• Female sex
• Lower socioeconomic status
• Widowed, divorced, or separated marital status
• Chronic physical health/chronic pain
• Family history of depression
• Death of a loved one
• Caregiving
• Functional/cognitive impairment
• Lack/loss of social support/social isolation
• Significant loss of independence
• Insomnia/sleep disturbance

General Prevention

Limited, but growing body of evidence suggest these interventions to prevent depression in the elderly:

• Following traditional dietary patterns (e.g., Mediterranean, Japanese, or Norwegian)
• Increasing the consumption of foods rich in omega-3 polyunsaturated fatty acids (e.g., salmon, tuna, sardine, mackerel)
• Engaging in regular physical activity and exercise

Commonly Associated Conditions

Chronic disease (e.g., coronary artery diseases [CAD], cerebrovascular diseases [CVD], cancer, Parkinson disease)