Psychic and somatic anxiety symptoms as predictors of response to fluoxetine in major depressive disorder.

The purpose of this study was to examine whether the presence/severity of psychic and somatic anxiety symptoms predicted clinical response following a 12-week, flexible-dose (20-60 mg daily), open-label trial of fluoxetine for major depressive disorder (MDD). The presence and severity of psychic and somatic anxiety symptoms were assessed with the use of select subscales of the Symptom Questionnaire and the Hopkins Symptom Checklist among 518 outpatients with MDD. With the use of separate logistic regressions, we tested for the relationship between clinical response, baseline Hamilton Depression Rating Scale (HAM-D-17) scores, and subscale scores at baseline entered separately as independent variables Overall completion, response and remission rates for the trial were 64.2%, 55.4%, and 48.9%, respectively. All subscale scores selected for this analysis significantly predicted treatment response to fluoxetine. The presence/severity of psychic and somatic anxiety symptoms of MDD at baseline predicted an increased likelihood of non-response to fluoxetine in MDD. Studies examining whether specific treatment strategies are more effective than the selective serotonin reuptake inhibitors for MDD patients with high levels of co-morbid psychic and somatic anxiety symptoms are warranted.