The management of treatment-resistant depression remains a major public health problem. Several acute depression trials suggest that only 45% of the patients achieve remission state with antidepressant monotherapy. An increasing body of evidence is emerging suggesting that multi-action antidepressants might be more effective in treatment-resistant depressed patients than single-action agents. In this context, the purpose of the study was to assess the effectiveness of duloxetine in treatment-resistant major depressed outpatients.

We performed a prospective study assessing the efficacy of duloxetine in major depressed outpatients who did not achieve full symptom remission (CGI-S (severity) ≥ 3) after treatment of adequate dose and duration (more than 8 weeks) with at least either one SSRI or the SNRI venlafaxine. We excluded patients with a severe medical illness and a personality disorder. CGI-S was used as a measure of symptom severity and administered before the administration of duloxetine and 6 weeks later. Five patients had been treated with venlafaxine and the others with a SSRI (Fluoxetine, Paroxetine, Citalopram).

The sample included 10 patients (3 M, 7 F). We observed a very significant decrease in CGI-S scores (5 ± 0.45 to 1.2 ± 0.63, p < 0.0001) after treatment with duloxetine (dose between 20 and 60 mg). Remission was achieved in 90% of the patients. The tolerance was excellent.

This study suggests the potential interest of duloxetine in treatment-resistant depressed patients.