BackgroundDepression and depressive symptoms are highly prevalent in old persons but are potentially reversible. Full recovery is the main goal in the treatment of depressive episodes. Compared to clinical trials, observational studies of patients with depression in late life (DLL) show poorer prognoses in terms of response and remission. However, observational studies on the course of DLL are scarce.The aims of this study were to examine the course of DLL in terms of response, remission and symptom-specific changes as measured by the Montgomery and Asberg Depression Rating Scale (MADRS), and to explore which clinical variables were associated with the response and remission.MethodsThis is an observational, multicenter and prospective study of patients aged 60 years and older who were referred to treatment of depression in the department of old-age psychiatry at specialist health care services in Norway. The patients were evaluated with the MADRS at admission to and discharge from hospital. The mean, median, minimum and maximum values for days stayed in hospital were 68, 53, 16 and 301, respectively.Effect size (ES) was calculated to determine which MADRS symptoms changed most during the treatment. To assess the predictors for change in the MADRS score (continuous variable) and for remission and response (both dichotomous variables), regression models adjusting for cluster effects within center were estimated.ResultsOf 145 inpatients, 99 (68.3 %) had a response to treatment (50 % or more improvement of the MADRS score). Remission (MADRS score ≤9 at discharge) was experienced in 74 (51.0 %) of the patients. Of the individual MADRS items, “reported sadness” (ES =0.88) and “lassitude” (ES = 0.80) showed the greatest amount of improvement, and “concentration difficulties” (ES = 0.50) showed the least amount of improvement during treatment. Having a diagnosis of dementia was associated with a lower remission rate and less improvement in the MADRS score during the treatment. Poorer physical health was associated with a lower response rate. Having experienced previous episode(s) of depression was associated with a lower remission rate.ConclusionsRecurrent episodes of depression, poor somatic health and a diagnosis of dementia were found to be negative prognostic factors for the course of DLL. Clinicians should therefore pay close attention to these factors when evaluating treatment.Trial registrationClinicalTrials.gov NCT01952366.