Hierarchy of predictors of treatment response with an aggressive treatment approach. Main outcome, full response status at week 12; proportion of responders at 12 weeks, 60%. A change in HRSD score at week 4 of less than 45% from baseline predicts a less-than-half (43%) chance of responding at week 12. For the patients in this group, higher baseline anxiety predicts a 39% chance of responding at week 12. For patients with a higher baseline anxiety, a younger age of onset predicts a 32% chance of responding at week 12. (From Andreescu C, Mulsant BH, Houck PR, et al. Empirically derived decision trees for the treatment of late-life depression. Am J Psychiatry 2008;165:859; with permission.)