Neural Predictors and Longitudinal Neural Correlates of Deep Transcranial Magnetic Stimulation for Treating Major Depression
Condition: Major Depressive Disorder
MeSH terms: Depression; Depressive Disorder; Depressive Disorder, Major
Study type: Interventional
Phase: Phase 2/Phase 3

Summary: 
      Standard high frequency repetitive transcranial magnetic stimulation (HF-TMS) is a
      noninvasive method to activate or de-activate neurons in superficial regions of the brain
      through the induction of weak electric currents in the brain tissue produced by rapidly
      changing magnetic fields. Studies have generally shown standard HF-TMS to be effective in
      treating major depressive disorder (MDD), although treatment effects are often highly
      variable and there are several negative trials in the specialized literature. One reason for
      these discrepant results might be that standard HF-TMS only enables direct stimulation of
      superficial brain areas and, consequently, it is possible that the stimulation of deeper and
      more widespread brain regions could produce superior and more reliable results. Recently, a
      novel form of HF-rTMS (called deep transcranial magnetic stimulation or DTMS), that allows
      direct stimulation of much larger and deeper brain regions, has also been shown to be
      effective and safe in treating MDD. Neuroimaging studies have shown that standard HF-rTMS
      directly affects several superficial areas of the brain, but to date there is no data on the
      brain effects of DTMS. Thus, this study aims to explore, for the first time, the brain
      effects of DTMS in MDD. More specifically, we, the investigators, hope to identify possible
      neural predictors of clinical improvement after DTMS and also clarify the impact of DTMS in
      the brain activity over time. In this study, DTMS will be applied over the left side of the
      front of the head (a region known as the 'prefrontal cortex'), and will be compared with
      standard HF-TMS in terms of its effectiveness and brain effects. For this, subjects with at
      least moderate MDD will be randomized to receive daily DTMS or standard HF-rTMS treatment for
      4 weeks, and will undergo functional magnetic resonance imaging (fMRI) before and after
      treatment. fMRI is a neuroimaging technique that allows us to measure which areas of the
      brain are more or less 'active' in response to specific stimuli at a particular time. During
      the fMRI sessions, we will use a validated cognitive task on working memory. Our results
      could eventually lead us, among other things, to identify which depressed patients would be
      best candidates for receiving either standard HF-rTMS or DTMS, and which areas of the brain
      should be targeted by these neuromodulation techniques.
    


Intervention name(s): Deep Transcranial Magnetic Stimulation; Repetitive Transcranial Magnetic Stimulation
Intervention type(s): Device; Device
Intervention description(s): DTMS will be administered according to the following parameters: 18 Hz in 84 trains of 2 seconds duration, with 20 seconds inter-train interval (3,024 pulses per session) at 120% of the resting motor threshold; rTMS will be administered according to the following parameters: 18 Hz in 84 trains of 2 seconds duration, with 20 seconds inter-train interval (3,024 pulses per session) at 120% of the resting motor threshold.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Major Depression; Functional Magnetic Resonance Imaging; Deep Transcranial Magnetic Stimulation; Repetitive Transcranial Magnetic Stimulation; rTMS; DTMS; fMRI; Randomized, Sham-Controlled Trial