Quetiapine Fumarate as Monotherapy in the Maintenance Treatment of Patients With Major Depressive Disorder

A Multi-Centre, Double-Blind, Randomised-Withdrawal, Parallel-Group, Placebo-Controlled Phase III Study of the Efficacy and Safety of Quetiapine Fumarate Sustained Release (SEROQUEL SR™) As Monotherapy in the Maintenance Treatment of Patients With Major Depressive Disorder

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00278941

Acronym

AMETHYST

Enrollment

3000

Registered

2006-01-19

Start date

2005-12-31

Completion date

2007-08-31

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

Seroquel SR™, Major Depressive Disorder

Brief summary

The purpose of this study is to determine safety & efficacy of SEROQUEL SR™ in the treatment of major depressive disorder compared to placebo & to evaluate quality of sleep, overall quality of life, and effect, if any, on anxiety and satisfaction PLEASE NOTE: Seroquel SR and Seroquel XR refer to the same formulation. The SR designation was changed to XR after consultation with FDA.

Interventions

DRUGQuetiapine Fumarate Sustained Release

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

* Documented clinical diagnosis according to the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision) meeting criteria 296.2x Major Depressive Disorder, * Single Episode, or 296.3x Major Depressive Disorder,

Exclusion criteria

* Patients with a DSM-IV Axis I disorder other than MDD w/in 6 months of enrollment, * Patients with a diagnosis of DSM-IV Axis II disorder which has a major impact on the patients current psychiatric status. * Patients whose current episode of depression\>12 months or \<4 weeks from enrollment

Design outcomes

Primary

Measure	Time frame
To evaluate the efficacy of quetiapine SR compared to placebo in increasing time from randomisation to a depressed event in patients with Major Depressive Disorder (MDD)	—

Secondary

Measure	Time frame
Evaluate quetiapine SR compared to placebo on health related quality of life.	—

Countries

Bulgaria, Canada, Puerto Rico, Romania, Russia, Slovakia, United Kingdom, United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026