What are the diagnostic criteria for major depression in an elderly patient?

Diagnostic Criteria for Major Depression in Elderly Patients

The diagnosis of major depression in elderly patients should be made using standardized assessment tools, with the Geriatric Depression Scale (GDS) being the preferred instrument for this population, using a score ≥5 on the 15-item scale or ≥19 on the 30-item scale to indicate depression. 1

Screening and Initial Assessment

Two-Step Screening Approach

1. Initial screening questions (PHQ-2):

   • "Over the past 2 weeks, have you felt down, depressed, or hopeless?"
   • "Over the past 2 weeks, have you felt little interest or pleasure in doing things?" 2
   • If either question scores ≥2 (occurring more than half the days or nearly every day), proceed to full assessment

2. Full assessment using either:

   • PHQ-9 with a cutoff score of ≥8 (more sensitive in elderly) 2
   • Geriatric Depression Scale (GDS) - preferred for older adults as it focuses on affective symptoms rather than somatic complaints that might be confounded by physical health conditions 1

DSM Diagnostic Criteria for Major Depression in Elderly

Five or more of the following symptoms present during the same 2-week period, representing a change from previous functioning, with at least one symptom being either depressed mood or loss of interest/pleasure:

1. Depressed mood most of the day, nearly every day
2. Markedly diminished interest or pleasure in all or almost all activities
3. Significant weight loss or decrease in appetite
4. Insomnia or hypersomnia nearly every day
5. Psychomotor agitation or retardation nearly every day
6. Fatigue or loss of energy nearly every day
7. Feelings of worthlessness or excessive guilt nearly every day
8. Diminished ability to think or concentrate nearly every day
9. Recurrent thoughts of death or suicidal ideation

Special Considerations in Elderly Patients

Atypical Presentation

• Depression in older adults often presents differently than in younger populations:
  • More somatic complaints
  • Less likely to report sadness
  • More likely to report memory problems
  • More irritability and anxiety
  • More likely to have psychomotor changes 1, 3

Medical Evaluation

• Medical causes of depression must be ruled out:
  • Thyroid dysfunction
  • Electrolyte abnormalities
  • Medication side effects
  • Vitamin B12 or folate deficiency
  • Anemia
  • Chronic infections 4

Cognitive Assessment

• Cognitive screening is essential as depression and dementia frequently co-occur in elderly patients
• Depression with cognitive impairment may represent:
  • Depression with pseudodementia
  • Depression comorbid with dementia
  • Early manifestation of dementia 3

Risk Factors Specific to Elderly Patients

• Medical comorbidities (especially cardiovascular disease)
• Polypharmacy
• Functional limitations
• Social isolation and loss of support systems
• Recent bereavement
• History of depression
• Chronic pain
• Sensory impairments (hearing/vision loss) 3, 5

Severity Assessment

• Mild depression: Few symptoms beyond minimum criteria, minor functional impairment
• Moderate depression: Symptoms or functional impairment between mild and severe
• Severe depression: Most symptoms present, marked functional impairment, with or without psychotic features 2

Suicide Risk Assessment

Suicide risk assessment is particularly important in elderly patients as they have the highest suicide completion rates of any age group:

• Assess for suicidal thoughts, intent, plan, and means
• Evaluate risk factors: male gender, living alone, recent loss, physical illness, pain, functional impairment 6

Common Pitfalls in Diagnosing Depression in Elderly

1. Underdiagnosis due to:

   • Attributing symptoms to normal aging
   • Focus on physical rather than psychological complaints
   • Patient reluctance to report psychological symptoms 5

2. Misdiagnosis due to:

   • Overlap between depression symptoms and medical conditions
   • Cognitive impairment masking or mimicking depression
   • Side effects of medications 7

3. Failure to assess for bipolar disorder - late-onset mania is rare but possible

Diagnostic Algorithm

1. Screen all elderly patients using the two PHQ-2 questions
2. If positive, administer full GDS or PHQ-9
3. Conduct thorough medical evaluation to rule out organic causes
4. Assess cognitive function
5. Evaluate for psychosocial stressors and risk factors
6. Determine depression severity
7. Assess suicide risk
8. Consider specialist referral for complex cases, treatment resistance, or severe symptoms 1

Remember that depression in the elderly is not a normal part of aging and is treatable. Early identification and appropriate management can significantly improve quality of life and reduce mortality in this vulnerable population.