The objective of this study was to investigate whether
quetiapine, when compared with placebo, can speed the onset of action and improve the quality of response to
fluoxetine treatment in patients suffering from
major depressive disorder. A total of 114 patients with
major depressive disorder were enrolled in an 8-week treatment study. Patients were initiated on a course of
fluoxetine treatment and randomized to
quetiapine or placebo.
Quetiapine was flexibly dosed starting at 25 mg to a maximum of 100 mg daily. Mixed-effects regression showed that
quetiapine plus
fluoxetine did not achieve 50% reduction in the Montgomery-Asberg Depression Rating Scale score or improvement in Hamilton Anxiety Scale, Clinical Global Improvement (CGI)-Severity, and CGI-Improvement scores sooner than the
fluoxetine plus placebo group; however both groups improved in all scores over time. Mixed-effects linear regression of
insomnia scores showed that the
quetiapine plus
fluoxetine group improved significantly more rapidly compared with the
fluoxetine plus placebo group. The study indicates that
quetiapine plus
fluoxetine did not achieve a reduction in the Montgomery-Asberg Depression Rating Scale score or improvement in Hamilton Anxiety Scale or CGI scores from baseline sooner than the
fluoxetine plus placebo group. The combination of
quetiapine and
fluoxetine, however, improved sleep over
fluoxetine alone over the first few weeks of treatment.