Conditions: Major Depressive Disorder (MDD)
Keywords: Major Depressive Disorder MDD Depression
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 211
Healthy volunteers: no

Brief summary:
This will be a multicenter, randomized, double-blind study designed to assess the efficacy, safety and tolerability of an oral Aripiprazole/Escitalopram combination therapy in participants with MDD who have demonstrated an incomplete response to a prospective trial of Escitalopram, and report a treatment history for the current MDD episode of an inadequate response to at least one and no more than three adequate trials of an approved antidepressant other than Escitalopram. An inadequate response is defined as less than a 50% reduction in depressive symptom severity as assessed by the participant's self-report on the Massachusetts General Hospital Antidepressant Treatment Response Questionnaire (ATRQ) and evaluated by the investigator as part of the participant's medical and psychiatric history. An adequate trial is defined as an antidepressant treatment for at least 6 weeks duration (or at least 3 weeks for combination treatments) at an approved dose as specified in the ATRQ.

Detailed description:
The study will be organized as follows:

* Screening Phase
* Single-blind Prospective Treatment Phase
* Single-blind Continuation Phase (Responder) or Double-blind Randomization Phase (non-Responder)
* 30 day Post Treatment Follow-up

Assigned Interventions:

* Escitalopram monotherapy
* Aripiprazole/Escitalopram combination therapy
* Aripiprazole monotherapy

Arms:
arm 1: Participants received initial dose of escitalopram 10 milligram (mg) blinded capsule (over-encapsulated tablet), orally, once daily, increased to 20 mg/day at the end of Week 1 based upon tolerability profile, for up to maximum of Week 8. No dose reductions were allowed after Week 4 and no dose increments were allowed after Week 3. Participants with incomplete response at the end of the Phase B (Week 8) entered Phase C and the rest of the participants continued to Phase B+. arm 2: Participants with response (≥50% reduction in depressive symptom severity in Hamilton Depression Rating Scale {HAM-D17} Total Score; or a HAM-D17 Total Score of \<14 at Week 8 or a Clinical Global Impression of Improvement {CGI-I} Score of \<3 at the Week 6 or 8) at the end of the Phase B (Week 8) continued treatment with the single-blind escitalopram monotherapy at the dose (10 or 20 mg/day blinded capsules) taken during the final week of Phase B, for up to maximum of Week 14, in Phase B+. arm 3: Participants with incomplete response (less than 50% reduction in depressive symptom severity between Baseline and Week 8 measured by the HAM-D17 Total Score and HAM-D17 Total Score of ≥14 at Week 8 and CGI-I Score of ≥3 at Week 6 and 8) at Week 8 received initial dose of aripiprazole 6 mg blinded capsule, orally, once daily at Week 9. Participants were up titrated to aripiprazole target dose of 12 mg/day at Week 10 (if initial 6 mg/day dose was tolerated) or down titrated to 3 mg/day (if significant tolerability issues arise on initial 6 mg/day dose), and thereafter received same dose up to maximum of Week 14. No dose increases were allowed for aripiprazole after end of Week 12, however, doses might be decreased at any visit based upon tolerability. In combination with aripiprazole, participants received escitalopram (10 or 20 mg/day blinded capsules) taken during final week of Phase B for up to maximum Week 14, in Phase C. No dose adjustments allowed for escitalopram during Phase C. arm 4: Participants with incomplete response (less than a 50% reduction in depressive symptom severity between the Baseline and Week 8 as measured by the HAM-D17 Total Score and a HAM-D17 Total Score of ≥14 at Week 8 and a CGI-I Score of ≥3 at Week 6 and 8) at Week 8, received escitalopram dose (10 or 20 mg/day blinded capsules) taken during the final week of Phase B for up to maximum Week 14, in Phase C. No dose adjustments were allowed for escitalopram monotherapy during Phase C. arm 5: Participants with incomplete response (less than a 50% reduction in depressive symptom severity between the Baseline and Week 8 as measured by the HAM-D17 Total Score and a HAM-D17 Total Score of ≥14 at Week 8 and a CGI-I Score of ≥3 at Week 6 and 8) at Week 8, received initial dose of aripiprazole 6 mg blinded capsule, orally, once daily for Week 9. Participants were up titrated to the aripiprazole target dose of 12 mg/day at Week 10 (if the initial 6 mg/day dose was tolerated) or down titrated to 3 mg/day (if significant tolerability issues arise on the initial 6 mg/day dose), and thereafter received the same dose for up to maximum of Week 14. No dose increases were allowed for aripiprazole after the end of Week 12, however, doses might be decreased at any visit based upon tolerability.

Interventions: intervention 1: Escitalopram intervention 2: Aripiprazole intervention 3: Blinded capsule
Intervention descriptions: intervention 1: Escitalopram capsule administered orally, once daily without regard to meals. intervention 2: Aripiprazole capsule administered orally, once daily without regard to meals. intervention 3: Blinded capsule administered orally, once daily.

Protocol document: