Cutting Edge: TMS treatment is safe, eases depression just like medication, says expert

In recent times, brain stimulation therapies, that are non-invasive and use magnetic fields to stimulate nerve cells, have gained currency to treat psychological disorders just like medication or psycho-therapy. In fact, these are safe and their efficacy has been proven in many clinical trials. Which is why the Department of Psychiatry, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh, has adopted novel techniques in its mental health management protocols.
Dr Shalini Naik, Assant Professor of Psychiatry, who completed her post-doctoral fellowship in brain stimulation from NIMHANS, Bengaluru, before learning advanced brain stimulation techniques in the UK, said, “We were hit the lockdown but have resumed regular services over the last three months. So far, more than 300 patients have received Transcranial Magnetic Stimulation (TMS), mainly for depression, obsessive-compulsive disorder, substance use disorders, schizophrenia, post-stroke depression, migraine and tinnitus.”
Since 2016, PGIMER has been using novel techniques such as TMS and Transcranial Direct Current Stimulation (TDCS) for the treatment of psychiatric, neurological and ENT conditions.
TMS was invented as early as 1985 to deliver short magnetic pulses to the scalp. These painlessly traverse the skull and generate changes in the underlying nerve cells as well as their connections in the brain, said Dr Naik. This equipment works on Faraday’s principles of electromagnetic induction and is a classic example of using physics to bring about changes in the brain. Based on the pattern and rate of stimulation, it can either enhance or suppress underlying brain activity, says Dr Naik.
“In 1996, Pascual-Leone and colleagues used this unique property of TMS to cause focal (region-specific), non-invasive (without a surgical procedure) neuromodulation (change in neuronal activity) in a practically painless manner to treat patients with major depressive disorders. Over the last three decades, there have been several experiments to confirm these findings and today, TMS is a well-established treatment of major depression, a severe and common mental health condition that significantly contributes to the global disease burden,” she adds.
TMS is particularly leveraged in depression because of the various lines of neurobiological investigation that suggest individuals with depression had diminished activity in their left pre-frontal cortex, which slumped them into depression. TMS, when delivered at a rapid rate (10-20 pulses in a second), can improve one’s mood enhancing the left pre-frontal brain activity. It is usually adminered in 30-45-minute daily sessions for four weeks. “Recent advances allow us to precisely locate the target brain regions using the patient’s own MRI scan images,” says Dr Naik.
She adds, Electroconvulsive Therapy (ECT) has no substitute and remains the first line of treatment because of its effectiveness, though the ethical questions remain. Doctors make an informed decision about using these brain stimulation techniques based on how a patient will benefit. “Here at PGI, we get patients who are resant to conventional treatments and have a poor prognosis. So, we base our decision to use TMS or TCDS based on several factors. In my opinion, medication is a long-term treatment,” she says.
Current evidence from robust and well-executed clinical trials suggests that TMS treatment eases depression just like medication or psychotherapy. However, given the high costs of the devices, the availability of effective alternative treatments, the limited number of trained specials and the limited availability of these devices, TMS is not frequently used to treat depression.

It is, therefore, essential to tailor the application of TMS to individuals who need it the most. These are patients who have partially responded or not responded to medication or individual psychotherapy, and those who cannot tolerate medication because of intolerable side effects. The beneficial effects of TMS last for a few months and Dr Naik advises that patients continue taking their medication unless otherwise indicated. TMS, she clarifies, does not prevent future episodes of depression.
A day-long care procedure, Dr Naik says the treatment is not painful and is safe though it is not used on patients who have a hory of seizures or have metallic implants.
Side effects of TMS are occasional discomfort at the site of scalp stimulation the TMS coil. There may be a rare occurrence of seizures. This happens only when safety guidelines are ignored or when the patient has had an earlier episode of seizure or epilepsy. A thorough screening to select patients with minimal risk for side effects and adminration of TMS with standard devices under prescribed stimulation guidelines are, therefore, necessary to limit side effects. “Often in our clinical practice, the prescription and adminration of TMS is an informed decision made the patient in consultation with his/her psychiatr after going through risks, benefits, cost-effectiveness and pragmatic implementation. Here at PGI, a patient was adamant about not taking medication for depression and for close to nine months he opted for brain stimulation techniques for his condition with good results. This was a rare case where no medication was prescribed. We observed good results in an elderly patient suffering from depression, who was not responding to medication. The aim is to prolong balanced brain activity,” adds Dr Naik.