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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
N-acetylcysteine in Unipolar depression
Scientific title
The Efficacy of N-acetylcysteine as an Adjunctive Treatment to improving depression in patients with Unipolar Depression: A Double-blind, Randomised, Placebo-controlled Trial
Secondary ID [1] 281088 0
NAC and UD
Secondary ID [2] 281230 0
NAC and UD
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Unipolar depression 1627 0
Condition category
Condition code
Mental Health 1735 1735 0 0

Study type
Description of intervention(s) / exposure
N-acetylcysteine will be administered 2mg/day in two 500mg capsules to be taken twice daily for a duration of 8 weeks. Patients will be randomly assigned to N-acetylcysteine.
Intervention code [1] 1596 0
Treatment: Drugs
Comparator / control treatment
Placebo will be administered 2mg/day in two 500mg capsules to be taken twice daily for a duration of 8 weeks. Patients will be randomly assigned to placebo group.
Control group

Primary outcome [1] 2412 0
The Montgomery Asberg depression Rating Scale (MADRS)
Timepoint [1] 2412 0
The scale will be administered at weeks 2, 4, 6 and 8 post-baseline intervals
Secondary outcome [1] 4188 0
The secondary outcomes include Clinical Global Impression - Improvement (CGI-I) and Severity (CGI-S), Global Assessment of Functioning Scale (GAF), Social and Occupational Functioning Assessment Scale (SOFAS), SLICE LIFE/LIFE RIFT, Quality of life Enjoyment & Satisfaction Questionnaire (Q-Les-Q).
Timepoint [1] 4188 0
These scales will be administered at weeks 2, 4, 6, and 8 post-baseline intervals.

Key inclusion criteria
Have capacity to consent, meet Diagnostic and Statistical Manual for Mental Disorders, Fourth edition, revision (DSM-IV-TR) criteria for major depressive disorder, have single episode or recurrent, achieve score of 18 or over on the MADRS at the time of trial entry, patients on antidepressant therapy need to have been on the same treatment for one month prior to randomisation, and if female of child bearing age and sexually active need to utilise effective contraception.
Minimum age
18 Years
Maximum age
Not stated
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
The exclusion criteria include individuals with concurrent diagnosis of bipolar I or II disorder, bipolar disorder not otherwise specified, electroconvulsive therapy for current depressive episode, concurrent primary diagnosis of a personality disorder, known or suspected clinically unstable systemic medical disorder, elderly subjects with respiratory insufficiency, recent gastrointestinal ulcers, pregnancy or breastfeeding, current use of greater than 500mg of NAC/day, 200mg of selenium or 500 IU of vitamin E/day, and history of anaphylactic reaction to NAC or any component of the preparation.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Treatment were randomly assigned into pack numbers by an individual independent of participant recruitment. Trial clinicians recruited participants and allocated them sequential pack numbers thereby adhering to double blind procedures.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Treatments were allocated into pack numbers by a simple coin tossing method. Participants were then recruited and allocated sequential pack numbers.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Neither investigators nor patients are aware of which treatment aim the patients have been allocated. The blindness will be remained until the completion of the study.
Phase 3 / Phase 4
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 1885 0
Name [1] 1885 0
Stanley Medical Research Institute
Address [1] 1885 0
8401 Connecticut Ave, Suite 200
Chevy Chase, MD 20815
Country [1] 1885 0
United States of America
Primary sponsor type
Mental Health Research Institute
Oak Street, Parkville
Secondary sponsor category [1] 1699 0
Name [1] 1699 0
Address [1] 1699 0
Country [1] 1699 0

Ethics approval
Ethics application status
Ethics committee name [1] 3508 0
Barwon Health
Ethics committee address [1] 3508 0
Ethics committee country [1] 3508 0
Date submitted for ethics approval [1] 3508 0
Approval date [1] 3508 0
Ethics approval number [1] 3508 0
Ethics committee name [2] 3509 0
Royal North Shore Hospital,
Ethics committee address [2] 3509 0
Ethics committee country [2] 3509 0
Date submitted for ethics approval [2] 3509 0
Approval date [2] 3509 0
Ethics approval number [2] 3509 0
Ethics committee name [3] 4415 0
Bendigo Health Care Group
Ethics committee address [3] 4415 0
P O Box 126, Bendigo, 3552
Ethics committee country [3] 4415 0
Date submitted for ethics approval [3] 4415 0
Approval date [3] 4415 0
Ethics approval number [3] 4415 0
Ethics committee name [4] 5110 0
Mental Health Research Institute
Ethics committee address [4] 5110 0
Locked Bag 11, Parkville 3052
Ethics committee country [4] 5110 0
Date submitted for ethics approval [4] 5110 0
Approval date [4] 5110 0
Ethics approval number [4] 5110 0

Brief summary
This is a novel study that investigates the benefits of NAC treatment in unipolar depression. Based on previous literature that reported deficits of this antioxidant in the brains of people with schizophrenia and bipolar disorder, the study postulates the deficits in unipolar depression patients. This trial involves adjunctive treatment where patients are received either NAC or placebo on top of their usual medication for a duration of 8 weeks.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 27530 0
Address 27530 0
Country 27530 0
Phone 27530 0
Fax 27530 0
Email 27530 0
Contact person for public queries
Name 10785 0
Professor Michael Berk
Address 10785 0
Mental Health, Swanston Centre
PO Box 281 Geelong, VIC, 3220
Country 10785 0
Phone 10785 0
03 5226 7450
Fax 10785 0
03 5226 7436
Email 10785 0
Contact person for scientific queries
Name 1713 0
Professor Michael Berk
Address 1713 0
Mental Health, Swanston Centre
PO Box 281 Geelong, VIC 3220
Country 1713 0
Phone 1713 0
03 5226 7450
Fax 1713 0
03 5226 7436
Email 1713 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary