NCT00326144 (OPAL) is a Phase 3 clinical trial of Quetiapine fumarate in Major Depressive Disorder, sponsored by AstraZeneca.

Who is sponsoring NCT00326144?

NCT00326144 is sponsored by AstraZeneca.

What drugs are being tested in NCT00326144?

Interventions in NCT00326144: Quetiapine fumarate.

What condition does NCT00326144 study?

NCT00326144 studies Major Depressive Disorder.

Is NCT00326144 still recruiting?

NCT00326144 is currently completed. Last updated 24 March 2009.

Last reviewed 2009-03-24 · How we verify

NCT00326144: OPAL

Name: Drug Landscape Pharmaceutical Database
Creator: Drug Landscape
Published: 2026-01-01
License: https://creativecommons.org/licenses/by/4.0/

A Multicenter, Double-Blind, Randomized, Parallel-Group, Placebo-Controlled Phase III Study of the Efficacy and Safety of Quetiapine Fumarate Sustained Release (Seroquel SR®) as Mono-Therapy in the Treatment of Adult Patients With Major Depressive Disorder

Completed Phase 3 Last updated 24 March 2009

What this trial tests

Phase 3 trial testing Quetiapine fumarate in Major Depressive Disorder in 310 participants. Completed in 1 May 2007.

Timeline

1 April 2006

1 May 2007

Quick facts

Lead sponsor	AstraZeneca
Phase	Phase 3
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	double
Primary purpose	treatment
Enrollment	310
Start date	1 April 2006
Estimated completion	1 May 2007
Sites	34 locations across United States

Drugs / interventions tested

Quetiapine fumarate — full drug profile →

Conditions studied

Major Depressive Disorder — all drugs for Major Depressive Disorder →

Sponsor

AstraZeneca — full company profile →

Who can join

Adults 18 to 65, any sex, with Major Depressive Disorder. Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

To evaluate the efficacy of Quetiapine SR compared with placebo in the treatment of patients with MDD as assessed by change from randomization to Week 8 in the MADRS total score

Sponsor's own description

The purpose of this study is to demonstrate superior efficacy of Quetiapine fumarate sustained release (SEROQUEL) compared with placebo when used as a mono-therapy in the treatment of Major Depressive Disorders PLEASE NOTE: Seroquel SR and Seroquel XR refer to the same formulation. The SR designation was changed to XR after consultation with FDA.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

Medication Nonadherence, "Professional Subjects," and Apparent Placebo Responders: Overlapping Challenges for Medications Development.
McCann DJ, Petry NM, Bresell A, Isacsson E, et al · · 2015 · cited 42× · PMID 26244381 · DOI 10.1097/jcp.0000000000000372
Early Symptom Improvement as a Predictor of Response to Extended Release Quetiapine in Major Depressive Disorder.
McIntyre RS, Gorwood P, Thase ME, Liss C, et al · · 2015 · cited 9× · PMID 26474010 · DOI 10.1097/jcp.0000000000000416

Verify or expand the search:

Other recruiting trials for Major Depressive Disorder

Currently open trials in the same condition.

NCT07219394 — Peer-Delivered Behavioral Activation in a CCBHC · NA · recruiting
NCT06705478 — Pramipexole Versus Escitalopram to Treat Major Depressive Disorder (MDD) and Comorbid MDD With Mild Neurocognitive Disor · Phase 2 · recruiting
NCT06749392 — An Individual-specific Synchrony Signature · NA · recruiting
NCT07316803 — Group Intervention for Romantic Relationships in Young Adults With Severe Mental Illness · NA · recruiting
NCT07242105 — Optimizing Brain Excitability in Depression · NA · recruiting

Other AstraZeneca trials

Trials by the same sponsor.

NCT06998095 — Tezepelumab (Tezspire) Regulatory Postmarketing Surveillance in Korea · not yet recruiting
NCT07431775 — Saphnelo Use in Females of Child-bearing Potential · not yet recruiting
NCT07516184 — Explore the Diagnostic Value of Bronchodilation Test With Portable Oscillometry in Asthma Diagnosis · NA · not yet recruiting
NCT07279935 — Osimertinib Combined With Chemotherapy in Patients Who Had Distant Recurrence After Adjuvant Osimertinib for EGFRm Resec · Phase 4 · not yet recruiting
NCT07279948 — A Single-arm Observational Study to Characterize the Demographic, Clinical Features and Outcomes of a Brazilian Cohort o · not yet recruiting

Verify against primary sources

ClinicalTrials.gov — authoritative US registry record
WHO ICTRP — international registry index
EU Clinical Trials Register
Sponsor press releases (Google)

Data sources for this page

Trial protocol + status: ClinicalTrials.gov NCT00326144 (US National Library of Medicine, public domain)
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by AstraZeneca
Last refreshed: 24 March 2009

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT00326144.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing