The trials, named APIC-TMS (Asia Pacific Individual Connectomics – Transcranial Magnetic Stimulation) and SPARK-D (Singapore’s Precision Approach for Relief from Depression), are catalysed by Temasek Foundation (TF) and the National Medical Research Council (NMRC) respectively, with a grant of S$1 million each.

Dr Tor Phern Chern, Senior Consultant, Department of Mood & Anxiety and Head of Neurostimulation Service, IMH, is the Principal Investigator for both clinical trials.

Major depressive disorder and TRD

Major Depressive Disorder, commonly known as “depression”, is the most common psychiatric disorder among adults in Singapore. The 2016 Singapore Mental Health Study found that 6.3% of the Singapore adult population—or 1 in 16 adults (aged 18 and above)—has experienced the disorder at some point in their lifetime.

Mild cases of depression may be managed with psychotherapy, while moderate to severe cases are typically managed with antidepressant medication to alleviate the symptoms. Yet, some patients may not reach the remission stage despite taking medications and undergoing therapies. Clinically, this is known as TRD.

There are no local studies on the prevalence of TRD. Figures from overseas literature vary with ranges between 12% to 55%¹ and 40% to 70%², depending on how the studies define TRD and the study methodologies.

TRD is usually managed through a stepwise treatment approach that includes optimising medication dosage, switching to a different class of medication, and augmenting or combining treatments, with the inclusion of non-pharmacological treatments such as electroconvulsive therapy (ECT) and standard TMS.

Standard TMS versus Personalised TMS

Standard TMS delivers stimulation to the same spot of the brain for all participants, using a manually manipulated holder.

On the other hand, personalised TMS is more targeted and precise. It uses individualised functional magnetic resonance imaging (fMRI) to find the ideal location in each patient’s brain that should be stimulated to treat his/her depression, and a high precision robot arm to target the stimulation.

This spot in the brain is unique for each individual and to identify it, an algorithm developed by Research Fellow Ruby Kong and Associate Professor Thomas Yeo from the Centre for Sleep and Cognition at NUS Medicine and NUS College of Design and Engineering, will be used to perform advanced analytics on the individual brain scans.

From left to right: Nurse Loida G Sawit, Dr Jonathan Lee, Consultant in the Department of Mood & Anxiety at the Institute of Mental Health (IMH), Associate Professor Thomas Yeo, Deputy Director of the Centre for Translational Magnetic Resonance at NUS Medicine, Nurse Geeta Kasinathan and Dr Tor Phern Chern, Senior Consultant in the Department of Mood & Anxiety and Head of Neurostimulation Service at IMH demonstrating how personalised TMS is applied on patients with TRD.

A/Prof Thomas Yeo, who is also Deputy Director of the Centre for Translational Magnetic Resonance Research at NUS Medicine and co-PI for the clinical trials, said, “Functional MRI is one of the few non-invasive approaches that can safely image the living human brain. By using this newly-developed machine-learning algorithm to clearly outline high-quality individualised brain networks from the limited quantity of functional MRI data, we are able to locate the exact spot unique to each patient, and stimulate it to treat their depression disorder as accurately as possible. These upcoming pilot trials provide a platform to demonstrate that the safety and efficacy from personalised TMS can be assured for patients with TRD who are undergoing this procedure.”