Do atypical features affect outcome in depressed outpatients treated with citalopram?

Depressed patients with atypical features have an earlier onset of depression, a more chronic course of illness, several distinctive biological and familial features, and a different treatment response than those without atypical features. The efficacy and tolerability of selective serotonin reuptake inhibitors (SSRIs) have not been fully evaluated in depression with atypical features. This report evaluates data from the Sequenced Treatment Alternatives to Relieve Depression (STARD) study to determine whether depressed outpatients with and without atypical features respond differently to the SSRI citalopram. Treatment-seeking participants with non-psychotic major depressive disorder were recruited from primary- and psychiatric-care settings. The presence/absence of atypical features was approximated using baseline ratings on the 30-item Inventory of Depressive Symptomatology - Clinician-rated. Following baseline assessments, participants received citalopram up to 60 mg/d for up to 14 wk. Baseline sociodemographic and clinical characteristics, and treatment outcomes, were compared between participants with and without atypical features. Of the 2876 evaluable STARD participants, 541 (19%) had atypical features. Participants with atypical features were significantly more likely to be female, younger, unemployed, have greater physical impairment, a younger age of depression onset, a longer index episode, greater depressive severity, and more concurrent anxiety diagnoses. Those with atypical features had significantly lower remission rates, although this difference was no longer present after adjustment for baseline differences. Depressed patients with atypical features are less likely to remit with citalopram than those without atypical features. This finding is probably due to differences in baseline characteristics other than atypical symptom features.