The UNIQUE study assessed the effect of Quetiapine fumarate augmentation on the overall depression status of patients with major depressive disorder and who did not respond to any acute treatment with selective serotonin reuptake inhibitors (SSRIs) or selective noradrenalin reuptake inhibitors (SNRIs) and naïve to any atypical antipsychotics.

Between March 2006 and November 2007, 39 male and female patients, aged 18-65, were enrolled into this four-week, open label, non-comparative, multicentric, phase II prospective study. Treatment with Quetiapine fumarate began at enrolment, with a titration to a target dose of 300mg. The following scales were completed during all five visits: Montgomery-Asberg Depression Rating Scale (MADRS); Clinical Global Impression (CGI); Brief Psychiatric Rating Scale (BPRS); Sheehan Disability Scale (SDS).

All questionnaire mean scales were significantly reduced (Friedman P< 0.0001) at the end of the study from baseline: MADRS 16.9 (12.8-21.0); CGI 1.94 (1.52-2.37); BPRS 10.3 (6.7-13.6); SDS 8.5 (5.6-11.5). Response, defined as a reduction in MADRS total score >50% was observed in 45.9% of the 37 patients completing at least 2 weeks of the study and 37.8% were considered in remission e.g. MADRS total score ≤ 12 at visit 5.

Quetiapine fumarate augmentation improved the overall depression status of patients resistant to SSRI or SNRI treatment.