The goal of the proposed study is to evaluate the efficacy and safety of switching to Vilazodone in patients with major depressive disorder (MDD) who are unresponsive to, only partially responsive to, or cannot tolerate a trial of the generic SSRI, citalopram (e.g., partially responsive means patients who report that their depressive symptoms have improved through the use of citalopram but that significant depressive symptoms persist; cannot tolerate refers to patient report of intolerable side effects that result in a desire to discontinue the medication). Seventy-two subjects with major depressive disorder who are still symptomatic or report intolerable side effects after a 6-week open-label trial of citalopram 20mg/day ( i.e. who are not classified as responders) will be randomized to receive a higher maximum dose of citalopram (40mg/day) or switch to vilazodone during the randomization phase of the trial for 6 weeks. The hypothesis to be tested is that vilazodone will result in greater rates of treatment response and be better tolerated compared to being titrated up to a higher maximum dose (40mg/day) of citalopram. The proposed study will provide needed data on the efficacy of switching antidepressants when individuals do not fully respond to previous treatment or have intolerable side effects with a generic SSRI.
The purpose of this study is to evaluate the safety and effectiveness of vilazodone for the treatment of major depressive disorder versus citalopram. Doctors want to determine if vilazodone is effective for the treatment of major depressive disorder in those who have not responded to generic selective serotonin reuptake inhibitors (SSRI), which is a class of anti-depressant drugs such as Prozac, Lexapro, Paxil, or Zoloft. Both vilazodone and citalopram have been approved for the treatment of major depressive disorder. This research is being done because the researchers want to find out if vilazodone works in reducing the symptoms of depression significantly more than a generic SSRI.