Minocycline as Adjunctive Treatment for Treatment Resistant Depression

  • End date
    Aug 20, 2022
  • participants needed
  • sponsor
    Centre for Addiction and Mental Health
Updated on 22 August 2021
adjunctive treatment
depressive disorder
depressive symptoms
depressive episode
a 12


Major depressive disorder (MDD) is a leading cause of disability worldwide. Up to 50% of patients experience treatment resistant depression (TRD), which accounts for a vast majority of disease burden. Current medications for TRD have limited efficacy and can be associated with intolerable side effects. Therefore, there is a need for finding new treatment targets. Accumulating evidence suggests some patients with MDD including those with TRD, display brain inflammation. Thus, patients with TRD may benefit from medications that can reduce this inflammation. Minocycline is an antibiotic which can cross the blood-brain barrier and has effects on several systems implicated in depression. The principal investigator led the first pilot study of minocycline as an add-on treatment in TRD demonstrating that it led to a significant reduction in depressive symptoms compared to placebo and these findings require replication in a larger sample to confirm the efficacy and tolerability of this treatment approach.

This study is a 12 week, double-blind, placebo-controlled trial of minocycline as add-on treatment for patients suffering from a major depressive episode who have failed to respond to at least two adequate trials of antidepressant treatment. After screening and randomization to the two parallel arms of the trial, 50 patients will receive minocycline added to treatment as usual (TAU) and 50 patients will receive placebo added to TAU. Clinical assessment will include the Hamilton Depression Rating Scale (HAMD-17), Clinical Global Impression scale (CGI), Patient Health Questionnaire (PHQ-9), and the Generalized Anxiety Disorder scale (GAD-7) at each study visit (screening, baseline, week 2, 6, and 12). Side effects checklists will be undertaken at each visit. Minocycline will be started at 100 mg once daily and will be increased to 100 mg twice daily at two weeks. Secondary outcomes include inflammatory biomarkers measured at baseline, weeks 6 and 12.

This trial will provide further evidence of minocycline's efficacy and acceptability as a treatment option for patients with TRD and provide insights into its mechanism of action.

Condition Treatment Resistant Depression
Treatment Minocycline
Clinical Study IdentifierNCT03947827
SponsorCentre for Addiction and Mental Health
Last Modified on22 August 2021


Yes No Not Sure

Inclusion Criteria

diagnosis of non-psychotic MDD
male or female 18-90 years old
currently taking one of the following antidepressants: Escitalopram, Citalopram, Sertraline, Venlafaxine, Duloxetine, Mirtazapine or Bupropion
on a medically acceptable form of birth control for women of childbearing age

Exclusion Criteria

intolerance to tetracyclines
treatment with anticoagulants, diuretics, retinoids, ergot alkaloids, antacids containing aluminium, calcium or magnesium, bismuth and zinc salts, quinapril
history of substance use
major unstable medical illness
pregnancy or intent to become pregnant
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact



Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note