Safety & Efficacy Study of Quetiapine Fumarate (SEROQUEL®) vs. Placebo and Active Control in Major Depressive Disorder

A Multicenter, Double-Blind, Randomized, Parallel-Group, Placebo-Controlled and Active-Controlled Phase III Study of the Efficacy and Safety of Quetiapine Fumarate Sustained-Release (SEROQUEL®) as Monotherapy in the Treatment of Patients With MDD

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00321490

Acronym

DIAMOND

Enrollment

600

Registered

2006-05-03

Start date

2006-04-30

Completion date

2007-05-31

Last updated

2009-03-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Major Depressive Disorder

Keywords

MDD, Quetiapine fumarate, sustained release, Depression

Brief summary

This study is to evaluate that (SEROQUEL®) quetiapine sustained-release is efficacious and safe in the treatment of patients with MDD.

Interventions

DRUGQuetiapine fumarate

DRUGDuloxetine

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

DOUBLE

Eligibility

Sex/Gender

ALL

Age

18 Years to 65 Years

Healthy volunteers

Inclusion criteria

* Patient has a documented clinical diagnosis of Major Depressive Disorder. * Be able to understand and comply with the requirements of the study. * Able to understand and provide written informed consent

Exclusion criteria

* Patients (female) must not be pregnant or lactating * Current or past diagnosis of stroke or transient ischemic attack (TIA).

Design outcomes

Primary

Measure	Time frame
Change from randomization to Week 6 in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score	—

Secondary

Measure	Time frame
Change from randomization to each assessment in the MADRS total score	—
MADRS response, defined as a ≥50% reduction from randomization in the MADRS total score at Week 6	—

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 3, 2026