Innovation Through Stimulation: The Cutting Edge of Mental Health Treatment

Innovation Through Stimulation: The Cutting Edge of Mental Health Treatment

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Dr. Daniel Blumberger
Associate Professor, Department of Psychiatry, University of Toronto
Clinician Scientist, Campbell Family Mental Health Research Institute, CAMH
Medical Head and Co-Director, Temerty Centre for Therapeutic Brain Intervention, CAMH




By: Darby Lowe
Photo by: Mikaeel Valli

Depression is currently the leading cause of disability around the world, affecting over 300 million people. Common treatments for depression include both psychological (e.g. cognitive behavioral therapy) and pharmacological (e.g. selective serotonin reuptake inhibitors) approaches. Despite advances in these treatment modalities over the past decade, more than one third of patients with depression do not respond to these “first-line” treatments. Moreover, some antidepressant medications can induce intolerable and systemic side effects. So, what are the alternatives for patients who do not respond to or tolerate these therapies?  

Dr. Daniel Blumberger, a clinician scientist at CAMH, has spent his career advocating for clinical research, with a passion for redefining treatment. Acting as the Medical Head and Co-Director at the Temerty Center for Therapeutic Brain Intervention, Dr. Blumberger is spearheading innovation as he investigates the benefits of brain stimulation as a therapeutic option for refractory psychiatric disorders.

In the early stages of his training, Dr. Blumberger treated patients with severe, treatment-resistant depression and was able to see the benefits of electro-convulsive therapy, or ECT, first-hand. ECT is a therapy often used as a last-resort for patients unresponsive to any other treatment and involves the application of an electric current throughout the brain of an anaesthetized patient. Dr. Blumberger described how the treatment had the ability to “transform someone within a matter of weeks,” acting as a “type of awakening” for acutely ill and catatonic patients.

In completing his training, Dr. Blumberger gained experience using ECT as well as other forms of brain stimulation, including transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), and magnetic seizure therapy (MST). Dr. Blumberger has since been part of numerous clinical investigations examining brain stimulation as a therapeutic intervention for a variety of psychiatric disorders.

Currently, Dr. Blumberger and his team are investigating a novel type of TMS called theta burst stimulation (TBS) in young adults with treatment-resistant depression. TBS stimulates the brain with theta frequencies (4 to 7 Hz) similar to naturally occurring neural oscillations found in the brain, and can be performed in sessions as short as three minutes. This is compared to TMS, which involves magnetic stimulation of the brain with a frequency of 10Hz over multiple sessions roughly half an hour in length. Almost half of the participants in each brain stimulation modality group showed marked improvement of at least a 50% reduction in depressive symptoms, as well as increased energy and concentration and decreased suicidal ideation.

“The improvement in the patient’ overall quality of life, such as regaining their ability to function and go back to work, is particularly important,” says Dr. Blumberger. “We were also able to demonstrate that both TMS and TBS have similar clinical efficacy, and a major clinical implication of this finding is that TBS provides a shortened therapeutic session (three minutes compared to 30).” Therefore, TBS could facilitate a larger clinical impact by increasing the number of patients that can be treated each day.

Another area of Dr. Blumberger’s research aims to improve accessibility to brain stimulation treatment by investigating the application of tDCS as a relapse-prevention intervention in individuals who have previously responded to TMS. tDCS provides a much lighter form of stimulation to the brain and can be used by the patient in their own home. The theory, according to Dr. Blumberger, is that tDCS, which is a “plasticity-enhancing treatment,” will maintain the therapeutic changes that were imparted by TMS and therefore prevent relapse. If this is the case, the at-home treatment would minimize the travel burden for patients, therefore making therapeutic brain stimulation more accessible to all populations.

When asked why brain stimulation is an important area of research, Dr. Blumberger emphasizes its minimal side effects. Compared to pharmacological interventions that can produce serious systemic side effects, such as weight gain and bleeding disorders, brain stimulation techniques produce only minor side effects (e.g. headache, scalp discomfort). Moreover, Dr. Blumberger describes a future collaborative study in which functional magnetic brain imaging will be used concurrently with brain stimulation to biologically phenotype and potentially personalize treatment to one’s underlying dysfunction. He describes how, because of the high prevalence of depression and associated disability, as well as the high rates of treatment resistance in many patients, more options need to be available. “That’s why TMS is a very important treatment,” he explains, “it has demonstrated efficacy, it has the potential to be a personalized treatment, and it targets the brain without systemic side-effects.”

Dr. Blumberger’s work is aiming to transform brain stimulation into a safe, personalized and accessible form of medicine that may eventually be offered earlier in the care pathway of patients with depression. Dr. Blumberger’s motivation for his work researching and clinically practicing brain stimulation speaks for itself: “We are trying to advocate for these treatments because they are effective, have good tolerability and offer a new option for debilitating illness.”



Depression [Internet]. World Health Organization. World Health Organization; 2018 [cited 2019Mar15]. Available from

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Blumberger DM, Vila-Rodriguez F, Thorpe KE, Feffer K, Noda Y, Giacobbe P, Knyahnytska Y, Kennedy SH, Lam RW, Daskalakis ZJ, Downar J. Effectiveness of theta burst versus high-frequency repetitive transcranial magnetic stimulation in patients with depression (THREE-D): a randomised non-inferiority trial. The Lancet. 2018 May 4;391(10131):1683-92.