Introduction

Transcranial Magnetic Stimulation (TMS) is an innovative therapy gaining recognition for its benefits in treating various mental health conditions. This non-invasive procedure involves stimulating specific regions of the brain using magnetic fields, offering promise for those seeking alternatives or enhancements to traditional treatments like medication or therapy. 

Repetitive transcranial magnetic stimulation (rTMS) involves the repetitive application of magnetic pulses to target specific areas of the brain.¹ TMS has shown effectiveness in alleviating symptoms of depression, anxiety, and even certain neurological disorders, with minimal side effects. The U.S. Food and Drug Administration (FDA) has approved TMS to treat major depressive disorder, obsessive-compulsive disorder, and smoking cessation.² Whereas, in the UK, The National Institute for Health and Care Excellence (NICE) has approved TMS for the treatment of severe depression and anxiety only and is solely offered to people who do not respond to antidepressants or therapy. 

In this article, we will delve into the types of TMS, how TMS works, its advantages, and the potential applications of TMS in various conditions.

Types of transcranial magnetic stimulation

TMS comes in various forms, each designed for specific applications and targeting different areas of the brain. Here are some types of TMS:^1,3

Single-pulse transcranial magnetic stimulation (sTMS)

sTMS is a type of TMS where single magnetic pulses are delivered to the brain. It is used for diagnostic purposes, such as mapping cortical excitability (sensitivity level of the brain). It is also being explored for therapeutic applications.

Paired-pulse transcranial magnetic stimulation (ppTMS)

This method sends two quick magnetic pulses to the brain. It helps scientists study how different brain areas connect and change. ppTMS could be useful for understanding and treating brain-related issues like depression or memory problems.

Repetitive transcranial magnetic stimulation (rTMS)

This is the most common form of TMS. It involves delivering repeated pulses of magnetic energy to specific areas of the brain. It's often used to treat depression, anxiety, and certain neurological conditions.

Deep transcranial magnetic stimulation (dTMS)

This type of TMS uses a specialised coil designed to reach deeper areas of the brain than other conventional TMS coils. It's primarily used for treating depression and other mood disorders.³

How does transcranial magnetic stimulation work?

TMS works by placing a coil near the scalp to generate magnetic pulses. These pulses induce electrical currents within the brain, specifically targeting certain regions. This stimulation changes neuronal activity by influencing the flow of ions across cell membranes and altering the firing patterns of neurones. 

The magnetic field generated by the coil can penetrate the scalp and skull without causing harm to the surrounding tissues. Through this mechanism, TMS has the potential to alter brain function temporarily, offering a non-invasive method for investigating and regulating various cognitive and motor processes.⁴

Advantages of transcranial magnetic stimulation 

TMS offers several advantages as a therapeutic intervention for neurological and psychiatric conditions. These include:

• Long-lasting results
• Minimal side effects compared to medications and electroconvulsive therapy (ECT)
• Non-invasive treatment
• Reduced need for medications
• Does not interfere with driving, work or daily activities
• Not painful
• No recovery time
• Shorter treatment time
• Drug-free
• Effective in treatment-resistant depression
• No sedation or anaesthesia is required
• No withdrawal symptoms
• No memory issues
• Outpatient-based procedure

Health benefits of transcranial magnetic stimulation

TMS presents a versatile therapeutic approach with demonstrated efficacy across a spectrum of neurological and psychiatric disorders. Below, we delve into its benefits in addressing specific conditions:

Depression

TMS therapy has been FDA-approved since 2008 and NICE-approved since 2015 for the treatment of major depressive disorder (MDD) and treatment-resistant depression. Here are some key benefits of TMS for depression.

Reduced risk of side effects

A study revealed that patients undergoing TMS treatment reported fewer side effects compared to those who were prescribed antidepressants, including:⁵

• Nausea 
• Appetite changes 
• Fatigue 
• Insomnia
• Gastrointestinal issues

Effective for treatment-resistant depression

Studies have shown that TMS can provide beneficial effects for people who do not respond to traditional treatment methods (e.g., antidepressants and talking therapies). It was found that 60% of patients experienced an improvement in their symptoms after TMS.⁶

Potential to eliminate medication

TMS may replace medication for individuals with treatment-resistant depression, as evidenced by a study reporting a 40% remission rate. This surpasses the 20-39% remission rate of selective serotonin reuptake inhibitors (SSRIs).⁷ Another study found that approximately 58% of people in TMS therapy responded to treatment, and 37% had a full remission.⁵ That said, it is likely TMS will be used in conjunction with existing treatments to ensure optimal recovery and results. 

Obsessive-compulsive disorder (OCD)

TMS therapy was FDA-approved in 2017 for the treatment of obsessive-compulsive disorder (OCD). A study found that about 45% of patients experienced reduced OCD symptoms after one month of TMS treatment. The procedure was compatible with other therapies and did not show any adverse or long-term effects.⁸

In the UK, the use of TMS therapy for treating OCD is yet to be fully approved. However, in 2020, NICE approved the use of TMS for research purposes only (i.e., clinical trials testing TMS for OCD).

Migraines

TMS therapy was FDA-approved in 2013 for treating pain associated with certain migraine headaches. TMS offers multiple benefits for migraine sufferers, including:⁹

• Reducing migraine frequency and intensity
• Converting chronic (long-term) migraines to episodic (separate short) ones, especially when combined with amitriptyline
• Blocking migraine attacks by interfering with pain signals

Smoking cessation

TMS therapy was recently FDA-approved in 2022 as an aid for short-term smoking cessation in adults. Studies found that 19.4% of people who received active TMS treatment quit smoking continuously for four weeks, while only 8.7% of those who received fake TMS treatment did the same. 

TMS offers a promising approach to smoking cessation, boasting improved quit rates, and reduced craving and cigarette consumption.¹⁰

The following are conditions TMS has shown potential to treat but has yet to receive approval due to limited research:

Attention deficit hyperactivity disorder (ADHD)

TMS shows promise as an alternative treatment for adolescent attention deficit/hyperactivity disorder (ADHD). These magnetic waves stimulate neurotransmitter production, facilitating an appropriate balance in the brain's electrical activity. Over several weeks of treatment, TMS may help regulate neurotransmitter production, reducing the effects of ADHD. 

Studies indicate improvements in ADHD symptoms, along with good safety and tolerability profiles. TMS could be an option for those who don't respond to standard medications, with no major adverse events reported.¹¹ 

Addiction

TMS may help reduce cocaine use and craving, as well as improve cognitive control in individuals with cocaine addiction. Its therapeutic effects may involve increased dopamine and glutamate function in specific brain circuits.¹²

Anxiety

TMS for anxiety offers non-invasive neuromodulation, targeting brain regions associated with mood regulation, which may help alleviate symptoms with minimal side effects. 

By stimulating neural circuits involved in anxiety, TMS can help rebalance brain activity, offering an alternative or adjunctive therapy for those who don't respond to traditional treatments.¹³

Alzheimer’s disease

TMS is seen as a potential treatment option for Alzheimer's disease because it's safe, doesn't require surgery, and isn't very expensive. 

TMS may improve cognitive function in Alzheimer's patients, especially when the treatment targets specific areas of the brain based on individual brain scans. This approach helps balance brain activity and may have long-lasting effects, which could improve the overall wellbeing of Alzheimer's patients.¹⁴ 

Autism spectrum disorder (ASD)

Using low-frequency rTMS on a specific part of the brain called the dorsolateral prefrontal cortex has been reported to be helpful for individuals with autism spectrum disorder (ASD). It can improve how the brain processes information and reduce certain symptoms of ASD, like irritability and repetitive behaviours.¹⁵

Bipolar disorder

TMS for bipolar disorder targets the left dorsolateral prefrontal cortex, improving emotional regulation by stimulating this brain region with high accuracy. Its ability to precisely target specific areas associated with the disorder makes TMS a future treatment option for bipolar symptoms.¹⁶

Parkinson’s disease

TMS holds promise for alleviating motor symptoms like slowness of movement and tremors in Parkinson's disease by regulating cortical excitability. Its non-invasive nature and potential neuroprotective effects make it a valuable adjunctive therapy for managing symptoms and slowing disease progression.¹⁷

Post-traumatic stress disorder (PTSD)

TMS has been shown to reduce PTSD symptoms, with studies demonstrating efficacy and safety, including when combined with psychotherapy. Its mechanism involves modulating neural networks involved in PTSD, offering a non-pharmacological alternative with potential for long-term effects and broader applicability in treating psychiatric conditions.¹⁸

Schizophrenia

TMS may alleviate symptoms of schizophrenia by regulating neural activity in specific brain regions involved in the disorder. While further research is needed, early studies suggest TMS may offer a non-invasive, adjunctive therapeutic option for individuals with schizophrenia, by improving cognitive function and reducing symptom severity.¹⁹

Stroke rehabilitation

TMS is a potential treatment for stroke recovery, improving movement, thinking, mood, and overall quality of life for survivors. It targets specific brain activity and can be combined with other therapies for comprehensive rehabilitation.²⁰

Summary

• Transcranial Magnetic Stimulation (TMS) offers non-invasive treatment for various mental health conditions like depression, anxiety, and PTSD. 
• Its benefits include minimal side effects compared to medication or electroconvulsive therapy (ECT), making it suitable for those intolerant to drugs or seeking alternative options. 
• TMS targets specific brain regions involved in mood regulation, promoting neuroplasticity and restoring normal brain function. 
• The procedure is outpatient-based and requires no anaesthesia, allowing individuals to resume daily activities immediately. 
• With its high efficacy rates and long-lasting results, TMS stands as a promising therapeutic option, particularly for treatment-resistant cases, offering hope for improved mental wellbeing.