Background: The purpose of this study was to examine whether treatment response to fluoxetine by depressed outpatients was predicted by early improvement on any of 3 subscales (Anxiety, Depression, and Anger/Hostility) of the Symptom Questionnaire (SQ).
Methods: We evaluated 169 depressed outpatients (52.6% female) between ages 18 and 65 (mean age, 40.3 +/- 10.6 years) meeting DSM-IIIR criteria for major depressive disorder (MDD). All patients completed the SQ at baseline (week 0) and at weeks 2, 4, and 8 of treatment with fluoxetine 20 mg/d. We defined treatment response as a > or= 50% reduction in score on the 17-item Hamilton Rating Scale for Depression, and early improvement on 3 SQ subscales (Anxiety, Depression, and Anger/Hostility) as a >30% reduction in score by week 2.
Results: The percentage of patients with significant early improvement in anger was significantly greater than the percentage of those with early improvements in anxiety or depression. When early improvement on the Anxiety, Depression, and Anger/Hostility subscales of the SQ were assessed independently by logistic regression, all 3 subscales were predictors of response to treatment.
Conclusions: Early improvement in anger, anxiety, and depressive symptoms may predict response to antidepressant treatment among outpatients with MDD.