Prevalence, correlates, and course of minor depression and major depression in the national comorbidity survey

Data from the National Comorbidity Survey are used to study the lifetime prevalences, correlates, course and impairments associated with minor depression (mo), major depression with 5-6 symptoms (:MD 5-6), and major depression with seven or more symptoms (MD 7-9) in an effort to determine whether mo is on a continuum with MD, There is a monotonic increase in average number of episodes, average length of longest episode, impairment, comorbidity, and parental history of psychiatric disorders as we go from mo to MD 5-6 to MD 7-9. In most of these cases, though, the differences between mo and MD 5-6 are no larger than the differences between MD 5-6 and MD 7-9,arguing for continuity between mo and MD. Coupled with the finding from earlier studies that subclinical depression is a significant risk factor for major depression, these results argue that minor depression is a variant of depressive disorder that should be considered seriously both as a target for preventive intervention and for treatment. The paper closes with suggestions regarding the analysis of mo subtypes in future longitudinal studies. (C) 1997 Elsevier Science B.V.