Subthreshold depression: characteristics and risk factors among vulnerable elders.

Objectives: This study examines symptoms of subthreshold depression among older adults in congregate housing, compared with their nondepressed peers, and tests a conceptual model of subthreshold depression. Hypotheses included that subthreshold depression would be characterized and distinguished by low energy, social withdrawal, and depletion, rather than sadness, and that subthreshold depressed elders would be distinguished by poorer health and functioning, loneliness, and grieving a recent loss.

Method: A self-administered survey was followed by a diagnostic interview by telephone to (N = 166) white and African-American residents of independent and assisted living apartments from six retirement communities, average age 82.9 years. The Mini International Neuropsychiatric Interview (MINI) determined depression status. The 30-item Geriatric Depression Scale was used to measure symptoms.

Results: Forty-six individuals (27.7%) were identified as subthreshold depressed, seven as suffering from major depression, and 113 as non-depressed. Subthreshold depression was characterized by low energy, difficulty with initiative, worries about the future, lack of positive affect, sadness and irritability. Negative affect symptoms such as sadness and irritability best discriminated the subthreshold group from the nondepressed. Risk factors for subthreshold depression in this sample included less education, lower socio-economic status, African-American race, grieving, and social loneliness.

Conclusion: Subthreshold depression in this group of residents of congregate housing was similar to the depletion experienced by many nondepressed elders, but further characterized by negative affect and lack of hope for the future. Social factors, such as socioeconomic status and personal losses, constituted greater risks for subthreshold depression than did health and functioning.