J Affect Disord. 2011 Mar;129(1-3):126-42. doi: 10.1016/j.jad.2010.09.015.

A tune in "a minor" can "b major": a review of epidemiology, illness course, and public health implications of subthreshold depression in older adults.

Meeks TW, Vahia IV, Lavretsky H, Kulkarni G, Jeste DV.

Source

Department of Psychiatry, University of California, San Diego, UCSD, United States.

Abstract

BACKGROUND:

With emphasis on dimensional aspects of psychopathology in development of the upcoming DSM-V, we systematically review data on epidemiology, illness course, risk factors for, and consequences of late-life depressive syndromes not meeting DSM-IV-TR criteria for major depression or dysthymia. We termed these syndromes subthreshold depression, including minor depression and subsyndromal depression.

METHODS:

We searched PubMed (1980-Jan 2010) using the terms: subsyndromal depression, subthreshold depression, and minor depression in combination with elderly, geriatric, older adult, and late-life. Data were extracted from 181 studies of late-life subthreshold depression.

RESULTS:

In older adults subthreshold depression was generally at least 2-3 times more prevalent (median community point prevalence 9.8%) than major depression. Prevalence of subthreshold depression was lower in community settings versus primary care and highest in long-term care settings. Approximately 8-10% of older persons with subthreshold depression developed major depression per year. The course of late-life subthreshold depression was more favorable than that of late-life major depression, but far from benign, with a median remission rate to non-depressed status of only 27% after ≥1 year. Prominent risk factors included female gender, medical burden, disability, and low social support; consequences included increased disability, greater healthcare utilization, and increased suicidal ideation.

LIMITATIONS:

Heterogeneity of the data, especially related to definitions of subthreshold depression limit our ability to conduct meta-analysis.

CONCLUSIONS:

The high prevalence and associated adverse health outcomes of late-life subthreshold depression indicate the major public health significance of this condition and suggest a need for further research on its neurobiology and treatment. Such efforts could potentially lead to prevention of considerable morbidity for the growing number of older adults.