[New numbers on the duration of major and minor depressive episodes in the general population; results from NEMESIS-2]

BACKGROUND: Relatively little research has been conducted that can reliably be used by psychiatrists, psychologists and general practitioners to estimate the recovery time of their patients suffering from depression. The treatment guideline for depression submits that half of those with mdd will recover within three months. AIM: To present the findings from nemesis-2 (the Netherlands Mental Health Survey and Incidence Study-2) on both the duration of depressive episodes in the general population and associated risk indicators. METHOD: The respondents that had developed a depressive episode between the first two follow-up assessments were selected; 286 with a clinical depression according to dsm-iv criteria (mdd) and 107 with a subclinical depression (MinDD). The episode duration was assessed with the Life Chart Interview. RESULTS: Half of the patients with mdd recovered within 6 months and 12% had not recovered after 3 years. The mean duration for mdd was 10.7 months. Better physical and mental health before depression onset predicted shorter duration. Longer duration was associated with comorbid dysthymia or anxiety disorder. In comparison, the median duration of MinDD was half the length of mdd (3 months), whereas the mean duration (8.7 months), the percentage that had not recovered after 3 years (10%) and risk indicators for episode duration hardly differed. CONCLUSION: In the guideline for depression it is assumed that half of those with mdd will recover within three months. Our study, however, found the median duration of mdd to be twice as long. Consequently, only a short period without active treatment can be justified. This paper also concludes that MinDD cannot be regarded as a transient, self-limiting mood state.