Repetitive Transcranial magnetic stimulation (TMS) uses magnetic fields to modulate brain activity. A novel form of repetitive TMS (rTMS), intermittent theta burst stimulation (iTBS), has emerged as a promising new treatment for depression. This technique may be advantageous due to its very short duration and potentially stronger effect on brain activity in comparison with standard rTMS. However, the exact effect of iTBS on the activity of the brain in clinical populations remains poorly understood. This project aims to improve understanding of the mechanisms of action of iTBS by comparing its neuronal effect to sham treatment in 22 individuals with a diagnosis of major depressive episode, using positron emission tomography (PET) and magnetic resonance imaging (MRI) in a double-blind cross-over experiment, followed by a 6-week daily treatment course of iTBS.
Eligibility
Sex
ALL
Min age
18 Years
Max age
55 Years
Healthy volunteers
No
Inclusion Criteria:
* Men or women aged 18 to 55 years of age
* Mini-International Neuropsychiatric Interview-confirmed diagnosis of MDD, as a single or recurring episode
* Symptoms of MDD have not improved after ≥ 1 but ≤ 7 adequate dose(s) of antidepressant trial(s) in the current depressive episode
* A baseline score of ≥ 15 on the 17-item Hamilton Rating Scale for Depression (HRSD-17)
* Have received a stable antidepressant regimen for at least four weeks prior to entering trial
* Are voluntary and competent to consent to study
* Can speak and read English
Exclusion Criteria:
* Current or past (\< 3 months) substance (including nicotine) or alcohol abuse/dependence, as defined in DSM-5 criteria
* Positive urine test for illegal substances, cannabis, or cotinine
* Suicide attempt in the past three months and/or active suicidal intent
* Pregnancy (confirmed by urine test) and/or lactation
* Psychotic features in the current episode
* Any comorbid mental health disorders (including, but not limited to lifetime history of psychotic disorders, OCD, PTSD and/or bipolar I or II disorder) with the exception of anxiety/panic disorders and ADHD
* Significant unstable medical or neurologic illness confirmed by medical history and blood test at baseline (e.g. uncontrolled diabetes, or renal dysfunction)
* Organic cause to the depressive symptoms (e.g. thyroid dysfunctions), as ruled out by the referring physician
* Contraindication for TMS (e.g., personal history of epilepsy or convulsion, metallic head implant, pacemaker)
* Contraindication for MRI (e.g. metallic implant, claustrophobia)
* Have undergone a prior PET or SPECT research study
* ECT or rTMS treatment in the current depressive episode
* Benzodiazepine use
* Have a body mass index (BMI) higher then 35 or lower then 18
* Any other condition that, in the opinion of the investigators, would adversely affect the participant's ability to complete the study
Primary outcome measure(s)
Neural mechanisms of iTBS measured by [18F]FDG uptake in the sgACC — 40 minutes after iTBS The primary outcome measure for Part I is the change in \[18F\]FDG uptake in the sgACC after iTBS.
Neuroimaging predictors of iTBS response to treatment - primary measures — 6 weeks The primary clinical outcome measures will be response to treatment and remission. Response to treatment will be defined as at least a 50% reduction in pre-treatment symptoms severity as measured by the mean HRSD-17 score at week 6. Remission will be defined as a HRSD-17 score lower or equal to 7 at week 6.
Trial sites (1)
Facility
City
Region
Status
The Royal Ottawa Mental Health Centre
Ottawa
Ontario
More The Royal Ottawa Mental Health Centre trials in Canada
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
We use cookies to analyse site traffic and improve your experience. With your consent, we may also use cookies for advertising. You can change your choice at any time.
