Objective: A recently proposed multidimensional method of staging treatment resistance in depression, the Maudsley Staging Method (MSM), has been shown to predict short-term outcome of treatment. This study tested whether the MSM predicts longer-term clinical outcome. We hypothesized that patients with higher scores on the MSM would experience a worse longer-term outcome in terms of time spent in a depressive episode and level of functional impairment.
Method: From May through July of 2008, we followed up patients with treatment-resistant depression discharged from an inpatient unit of an affective disorders service; all had MSM scores previously calculated from preadmission clinical data. We used the Longitudinal Interval Follow-up Evaluation (LIFE) chart to determine the monthly symptomatic course of depression blind to initial MSM scores. We employed a regression model to adjust for various confounding factors, including variable duration of follow-up, to determine the independent association of MSM scores with persistence of depressive disorder.
Results: We assessed 62 of 80 eligible patients (78%) in a median follow-up duration (interquartile range) of 29.5 (19.0-52.5) months. The MSM independently predicted (1) being in an episode for 50% or longer of the follow-up duration (OR = 2.11, 95% CI = 1.25 to 3.57), (2) being in an episode at the time of follow-up assessment (OR = 1.89, 95% CI = 1.17 to 3.05), (3) being persistently in an episode throughout the follow-up period (OR = 2.01, 95% CI = 1.14 to 3.54), and (4) total months spent in a depressive episode (OR = 1.22, 95% CI = 1.06 to 1.40). The MSM also predicted functional impairment. Antidepressant count and the Thase and Rush model did not independently predict persistence of depression or functional impairment.
Conclusion: The MSM appears to have reasonable predictive validity regarding the longer-term course of illness, particularly persistence of depressive episodes. The MSM may be a useful, and possibly an improved, alternative to existing models of staging of treatment-resistant depression.
©Copyright 2009 Physicians Postgraduate Press, Inc.