Naturalistic outcomes of minor and subsyndromal depression in older primary care patients.

To review the literature regarding the naturalistic outcomes of minor and subsyndromal depression ('Min/SSD') in older primary care patients, synthesizing and critiquing findings and discussing avenues for future research. The author obtained relevant articles from repeated computer-assisted literature searches over the past 15 years, and by reviewing the reference citations of the articles so obtained. A variety of relevant outcome domains were identified, as were important putative predictors, moderators, and mediators of outcome. In general, minor and subsyndromal depression each have comparable outcomes, outcomes that are clearly worse than non-depressed subjects, with substantially elevated risk of worsening into major depression, albeit not as poor as those with major depression. Min/SSD is common and of real clinical importance in primary care seniors. Several definitions of SSD may be used, each with overlapping but distinguishable utility in identifying patients. While the evidence base has expanded greatly in the past decade, considerable work remains to be done. Naturalistic studies of several outcome domains are needed, focusing on the predictive, moderating, and mediating roles of a wide range of psychopathological, medical, functional, and psychosocial factors. Such work will complement interventions and biomarker research approaches.