Over the past few years, there are several studies indicating the efficacy of Transcranial Magnetic Stimulation or TMS as an alternative depression treatment.
Researchers at Butler Hospital along with the collaboration of different clinics in the US confirmed the efficacy of TMS treatment for patients with depression who were unsuccessful on their antidepressant medications. Their finding is one of many first studies who delved into the use of TMS treatment. It was published on June 11, 2012 edition of Depression and Anxiety in the Wiley Online Library.
How did TMS Start?
Anthony Baker introduced TMS in 1985 at the University of Sheffield in England. It was intended as a neurodiagnostic tool used to produce an evoked potential in muscle tissue by activating neurons in the motor cortex. The whole concept of TMS was based on the two basic principles of physics; Faraday’s principle of electromagnetic induction and Ampere’s law.
Faraday’s principle involves the use of electromagnetic induction and that voltage can be measured and changed when generated across a length of wire – if the wire was left exposed to a perpendicular magnetic field flux of alternating intensity. Also, Ampere’s law state that the magnetic field can be managed around an electric current is proportional to the electric current.
TMS principle revolves around this principle. The stimulation coil consists of several wire loops encased in an insulating material. According to Kobayashi M, Pascual-Leone A. in Transcranial magnetic stimulation in neurology, “If a pulse of current is passed through this coil and placed over a person’s head, it produces rapidly changing magnetic pulses that penetrate the scalp and skull and reach the brain with minimal attenuation.”
Because of this, TMS can emit rapid and powerful but painless magnetic field that stimulates brain nerve cells. In doing so, it activates inactive region in the brain associated with depression.
Since its introduction in 1985, TMS had been studied as an alternative treatment for various mental disorders. Several studies show that TMS can be an effective treatment for major depression, Tourette syndrome, reducing auditory hallucinations in patients with schizophrenia, and obsessive-compulsive disorder. There a lot of evidence showing the efficacy of TMS in psychiatry.
Another Form of Electromagnetic Treatment
However, TMS was not the first treatment introduced that uses electromagnetic pulses. It was Electroconvulsive therapy (ECT) that was first used in 1938 which also show the significant result in treating major depression. Unfortunately, ECT uses an invasive method like anesthesia which resulted in severe side effects. It soon loses its popularity amongst patients with depressive disorders.
ECT remains one of the most controversial forms of treatment in the entire field medical science. It’s a love and hate relationships. But one film stands out in providing a wide range of people about the use ECT. The film “One Flew over Cuckoo’s Nest”, shows how crude treatment method ECT can get. Even though ECT can also effectively treat depressive symptoms, there has been a steady decline of its use in clinical psychiatry clinics.
A Safer Treatment Method
About 16.1 million people suffer from depressive disorders across the US. Depression is a serious illness affecting 350 million people worldwide; it’s becoming the largest health problem in the world. The medical community had developed medications and treatment plan to help manage its symptoms but there are patients who do not respond positively to these. Using medications often entails adverse side effects like tolerance and drug addiction.
The approval of FDA for TMS had cleared the TMS brain-stimulating device for treating depressive disorder to patients where antidepressant has failed to work. TMS brings new hope and vitality to patients and their families wherein it shows better results than the conventional treatment plan. It has far lesser and fewer side effects, some does not even experience and adverse reaction to TMS procedure.
TMS procedure shows its efficacy to over 24,000 people suffering from depressive disorder. About 1 out of 3 people have experienced complete remission from depression. While 50% of patients reported having significant reductions in their symptoms. The American Psychiatric Association also supports the use of TMS for patients who develop tolerance over their antidepressant medications. They suggest that medical professionals should consider TMS as a form of treatment rather than changing from one antidepressant to the other. Using antidepressant medications often lead to drug addiction.
One study conducted by Garcia-Toro M, Mayol A, Arnillas H, et al in their book entitled “Modest adjunctive benefit with transcranial magnetic stimulation in medication-resistant depression” shows that TMS can treat depression symptoms as effectively as any antidepressant medications.
More than 100 years in the making, we take a brief glance back at its origin and the concepts behind developing Transcranial Magnetic Stimulation
The idea of using electromagnetic currents to stimulate different body parts particularly the human brain in an attempt to treat various diseases can be traced back more than 100 years ago. It was the time where medical science began exploring the possibilities of electromagnetic efficacy. Unfortunately, technology at that time cannot keep up with the changing times and these studies are not approved by scientific data.
Theory Behind TMS
Anthony Barker and his colleagues first introduced the modern Transcranial Magnetic Stimulation (TMS) device what we know today in 1985. However, the physics behind the TMS machine originated from Michael Faraday and Ampere’s law.
Faraday’s theory used electromagnetic induction and that voltage can be measured and changed when generated across a length of wire – if the wire was left exposed to a perpendicular magnetic field flux of alternating intensity. Also, Ampere’s law state that the magnetic field can be managed around an electric current is proportional to the electric current.
TMS uses electromagnetic pulses to stimulate an area of the brain associated with depression. This activates neurons to rewire making emotions and mood behavior more manageable. When these electromagnetic pulses passed through a coil going to the head, the brain will be permeated easily. These activated the neurons directly without any serious adverse effects.
When these electromagnetic pulses intensified or rapidly changed, it generates a depolarizing effect in the brain nerve cells thus releasing neurotransmitters that regulate brain functions.
During the mid-1900’s researchers from the field of Psychiatry began exploring the effect of Repetitive Transcranial Magnetic Stimulation or rTMS in treating depressive disorders. After its initial start, more studies followed suit, focusing on the use of rTMS as a safe and alternative treatment for various mental disorders aside from depression.
Within a decade, around 90 clinical trials and several meta-analyses recommend the use and effects of rTMS in treating major depression.
Getting FDA Approval
Following the success of these different clinical trials, and based on the study of O’Reardon et al of using rTMS in the treatment-resistant major depression of 301 patients, the US Food and Drug Administration approved its use. TMS got its FDA approval in treating patients with the major depressive disorder.
The study shows how TMS can significantly improve the overall patient’s mood in comparison to conventional medications. Using TMS as part of depression management treatment proved as a safer and better alternative. Several years later, FDA finally announced in 2008 their approval of using rTMS machine as a major depression treatment.
Having a positive feedback from the FDA proved as a good starting point for rTMS in the management of Treatment-Resistant Depression. TMS efficacy in treating patients suffering from Treatment Resistant Depression is a major breakthrough in medical science. This devastating mental disease incapacitates millions of people, taking away their vitality and enthusiasm to live a normal life. Thus, the discovery of TMS and its usage is a great leap in providing these people another take on life.
Another pivotal study
Today, another version of TMS called deep rTMS or dTMS study which targets deeper brain structures had already started.
Launched in 2009, Dr. Xia’s research team at UC Davis started the endeavor of using dTMS for major depression. The study yielded very satisfactory findings. The remission rate of dTMS decreases for people with major depression by almost 50%. Enrolled patients comprised of highly treatment-resistant people who failed on their 2 or more medications in current index depression episode.
Because of its success and significant findings, the FDA approved the clinical use of dTMS immediately. As the study included patients who failed several times in their medication or already acquired intolerance to conventional treatment methods.
Right after this study, TMS became even more popular and widely accepted alternative treatment. More clinics started to accept its concept. Along with this, TMS convinced medical professionals and insurance coverage of its long-term benefits over other medications as well as ECT.
TMS Side Effects
Unlike other medications such as antidepressants, TMS does not have any systemic effects including sexual dysfunction, weight gain, nausea, tremors, diarrhea, headaches, constipation, sweating, anxiety, or sleepiness.
TMS does not produce any cognitive impairment as what ECT treatment produces. Patients who received ECT treatment usually suffer from memory impairment due to anesthesia or any muscle relaxant medications.
During TMS session, patients remain fully awake and alert on their environment. As TMS does not produce any major side effects, patients can immediately resume their daily activity. To this date, there are no reports that TMS had produced any long-term or life-threatening side effects.