Skip to content
Clinical Trials – home
Recruiting

Study of D-cycloserine with theta-burst brain stimulation for adults with major depressive disorder

Verified siteInvestigationalNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on treating patients with Major Depressive Disorder, a serious mental health condition characterized by persistent feelings of sadness and loss of interest in daily activities. The research combines two treatments: a technique called accelerated intermittent theta-burst stimulation (a form of brain stimulation) and D-cycloserine, a medication given as oral capsules.

The study aims to determine if adding daily 100 mg D-cycloserine capsules improves the effectiveness of brain stimulation treatment compared to a placebo in reducing depression symptoms. The treatment period lasts for nine weekdays, during which participants receive both brain stimulation and either the medication or placebo capsules. The placebo capsules look identical to the real medication but contain an inactive substance.

Participants will be monitored for changes in their depression symptoms through various assessments over a period of 180 days. The study includes regular check-ups to evaluate mood, anxiety levels, daily functioning, and overall well-being. Throughout the study, participants will take either D-cycloserine or placebo capsules, but neither the participants nor the healthcare providers will know which one they are receiving until the study is complete.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial evaluation

    Your depression symptoms will be evaluated using a special rating scale called MADRS (Montgomery-Asberg Depression Rating Scale) to confirm if you meet the study criteria.

    You must have experienced depression symptoms for at least 30 days and have a MADRS score of 20 or higher.

    Your current medications will be reviewed - they must remain unchanged for 4 weeks before and during the first 28 days of the study.

  2. Step 2

    Treatment phase

    The treatment will last for nine weekdays.

    You will receive either 100 mg of D-cycloserine or a placebo (inactive capsule) daily.

    The placebo capsule looks identical to the medication - it is orange in color and contains harmless cellulose.

    You will also receive a treatment called aiTBS (accelerated intermittent theta-burst stimulation) during this period.

  3. Step 3

    Follow-up assessments

    Your depression symptoms will be evaluated through video consultation at day 28.

    Additional assessments will occur on days 12, 42, and 180.

    The evaluations will include:

    - Depression symptoms assessment

    - Anxiety symptoms check

    - General health evaluation

    - Cognitive function testing

    - Brain activity measurements

  4. Step 4

    Study completion

    The final evaluation will take place on day 180.

    Your participation in the study will end after completing all required assessments.

    The total duration of your participation will be 180 days from the start of treatment.

Who can join the trial?

10 criteria

  • Must provide written consent to participate in the trial
  • Must be at least 18 years old when providing written consent
  • Female participants who can become pregnant must use adequate contraception
  • Must be able to read, speak, and understand Swedish
  • Must be able and willing to attend all study visits, including preparation sessions, follow-up appointments, and complete all study evaluations
  • Must be able to swallow capsules
  • Must have been diagnosed with major depressive disorder and currently experiencing a depressive episode lasting at least 30 days at screening time
  • Must have moderate to severe depression symptoms at screening, shown by a MADRS score of 20 or higher (MADRS is a scale used to measure depression severity)
  • Must have tried at least one standard antidepressant medication or psychotherapy without achieving satisfactory results
  • Must have been on the same antidepressant medications for at least 4 weeks before joining the study and must not plan to change medications during the first 28 days of the study

Who cannot join the trial?

15 criteria

  • Age below 18 years
  • Presence of psychotic symptoms (loss of touch with reality, including hallucinations or delusions)
  • History of seizures or epilepsy
  • Having metal objects in the head area (except for dental fillings)
  • Pregnancy or breastfeeding
  • Current use of specific medications that could interact with study treatment
  • Substance abuse (alcohol or drug dependency) within the past 6 months
  • Participation in other clinical trials within the past 30 days
  • Severe neurological conditions or brain injuries
  • Unstable medical conditions that require immediate treatment
  • History of not responding to depression treatments in the past
  • Having thoughts of self-harm that require immediate intervention
  • Inability to provide informed consent
  • Severe allergic reactions to medications similar to the study drug
  • Significant changes in psychiatric medications within the past 4 weeks
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • D-cycloserine

    This is an oral medication that works in the brain to help treat major depressive disorder. It is being studied as an add-on treatment to enhance the effects of brain stimulation therapy in people with depression.

  • Accelerated intermittent theta-burst stimulation (aiTBS)

    This is a non-invasive brain stimulation therapy that uses magnetic pulses to stimulate specific areas of the brain. It is delivered over nine weekdays and is designed to help improve symptoms of depression. This is a newer, faster version of traditional brain stimulation treatment.

What is already known about the treatment

D-cycloserine - An oral medication administered in tablet form that acts as a partial agonist at the glycine binding site of N-methyl-D-aspartate (NMDA) receptors in the brain. Originally developed as an antibiotic for tuberculosis treatment, it is now being studied in clinical trials for major depressive disorder (MDD) due to its potential to enhance neuroplasticity and improve the effectiveness of brain stimulation treatments. When used in combination with accelerated intermittent theta-burst stimulation (aiTBS), it may help modify neural pathways involved in depression, with current research exploring a daily dose of 100mg for treating severe depressive symptoms.

Investigated diseases

Major Depressive Disorder (MDD) - A mental health condition characterized by persistent feelings of sadness, loss of interest in activities, and decreased energy lasting for at least two weeks. The condition affects a person's thoughts, feelings, behavior, and physical well-being, often causing changes in sleep patterns, appetite, and concentration. People with MDD may experience recurring episodes of depression throughout their lives, with symptoms varying in intensity and duration. The condition can affect daily functioning, including work, social relationships, and overall quality of life. During depressive episodes, individuals may feel worthless, have difficulty making decisions, or experience changes in their activity levels.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-521686-27-01Estimated enrolment105 patientsSponsorRegion Uppsala

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).