Possible predictors of response to clonazepam augmentation therapy in patients with protracted depression

INTRODUCTION: Clonazepam has been shown to be an effective supplementary treatment for depression. Thus, it would be useful to determine which patient characteristics are associated with response to clonazepam. AIMS: The purpose of this study was to examine the possible predictors of response to clonazepam in the treatment of depression. METHOD: A retrospective cohort analysis was carried out in 120 patients with protracted depression who were being treated with clonazepam. RESULTS: A variety of clinical factors, including age, gender, type of depression, frequency of episodes, family history; and daily dose of clonazepam, were analyzed as possible predictors of response to clonazepam. A Weibull regression analysis showed that the factors that best predicted improvement with clonazepam augmentation were negative family history of psychiatric illness (e(coef) = 0.378), daily clonazepam dose of 2.5-4.0 mg (e(coef) = 0.160), and unipolar depression (e(coef) = 0.147). CONCLUSIONS: These factors should be considered when clonazepam augmentation therapy is selected for protracted depression.