Clinical trial No longer in our active list Phase 2 Interventional Ages 18 and up

Using D-Cycloserine to Enhance Brain Stimulation for Depression

Official title: D-Cycloserine Augmentation of Intermittent Theta Burst Stimulation (iTBS) in Depression: A Multi-Site, Randomised, Placebo-Controlled Trial (COGENT)

Run by The Alfred · NCT05591677 · Data updated 2026-05-14

This study is no longer in our active list. It may have stopped recruiting or finished. The details below are as of 2026-05-14 and are kept for reference. Check ClinicalTrials.gov for its current status, or see similar studies below.

This study is testing if the drug D-Cycloserine can make brain stimulation treatment work better for people with major depression.

Quick facts

PhasePhase 2
Study typeInterventional
Ages18 Years and up
SexAll
Enrollment180 (estimated)
SponsorThe Alfred
Academic / other
Locations1 site (Melbourne, Victoria)
Trial IDNCT05591677 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates include adults aged 18 and older with a diagnosis of major depressive episode and treatment-resistant depression.

Probably not a fit

Patients with unstable medical conditions, certain neurological disorders, or those currently using substances may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This clinical trial investigates whether the drug D-Cycloserine (DCS) can enhance the effects of Intermittent Theta Burst Stimulation (iTBS) in patients with Major Depressive Disorder (MDD). Participants will receive either 50mg or 100mg of DCS or a placebo before daily iTBS sessions over four weeks. The study aims to determine the effectiveness of DCS in improving depressive symptoms compared to iTBS alone, as well as assess the safety and tolerability of the drug. Clinical assessments will be conducted at various points throughout the treatment period to evaluate outcomes.

Why it matters

Potential benefit: If successful, this approach could provide a more effective treatment option for patients suffering from treatment-resistant depression.

How similar studies have gone: Previous studies have shown promising results with similar augmentation strategies in enhancing the effects of brain stimulation therapies.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Diagnosis of major depressive episode (MDE), in accordance with the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5), in the context of unipolar major depressive disorder or bipolar affective disorder.
* 18 years or older in age.
* Treatment resistant depression at Stage II of the Thase and Rush classification.56
* Baseline Montgomery Åsberg Depression Rating Scale score of ≥ 20 (moderate-to-severe depression severity).57,58
* No increase or initiation of new antidepressant therapy in the four weeks prior to screening.
* Demonstrated capacity to give informed consent.

Exclusion Criteria:

* Inability to provide informed consent.
* Medically unstable patients at the discretion of the investigator.
* Concomitant neurological disorder or a history of a seizure disorder.
* Participants who are pregnant.
* Current substance use meeting DSM-5 criteria for substance use disorder.
* Per DSM-5, had ever met diagnostic criteria for schizophrenia, schizoaffective disorder, schizophreniform disorder or delusional disorder as assessed by the Mini-International Neuropsychiatric Interview (MINI) at the time of screening.
* Diagnosis of any other mental disorder that is the participant's primary diagnosis or main mental health syndrome of concern at the time of screening, which may significantly affect psychiatric status and assessed as likely to impact trial participation, in the clinical judgement of the investigator.

Where it's running

  • Monash Alfred Psychiatry Research Centre
    Melbourne, Victoria, Australia
    Recruiting

Study contacts

Similar studies

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How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.