TMS for Anxiety
Anxiety disorders are the most common mental ailments in the U.S., affecting more than 18.1% of the adult population every year, according to the stats from the Anxiety and Depression Association of America (ADAA).
Why Consider TMS for Anxiety?
First-line Treatments for Anxiety do not Work for everyone
Anxiety disorders are treatable conditions and usually respond to first-line interventions such as medications and behavioral therapy. That said, research shows that these treatments only work in about 60% of patients. Many patients respond only temporarily while others still remain treatment-resistant.
Moreover, those that do not respond to first-line options have been shown to have the highest rates of suicidal attempts than any other disorders.
The Side Effect Profile of Anti-Anxiety Pills is Not Very Safe
The use of anti-anxiety medications comes at the risk of adverse effects, which can be as serious as suicidal ideations if someone stops them abruptly. The side effects of the pills may also lead to poor compliance. This shortfall may further have detrimental effects from the perspective of managing anxiety, causing the disorder to become more and more treatment-resistant.
How can TMS Work for Anxiety Disorders?
Neuromodulation via TMS has been gaining momentum as a promising tool for several illnesses, including those involving anxiety symptoms. Here are a few theories that may help elucidate the role of TMS in anxiety disorders.
Depression and Anxiety go Hand in Hand
While the U.S. FDA hasn’t yet approved TMS for the treatment of anxiety, psychiatrists have been prescribing it off-label owing to its beneficial effects. Moreover, it has long been established that depression and anxiety are typically seen together in many people. In fact, around 50% of patients diagnosed with depression have some form of anxiety disorder as well, better known as anxious depression.
TMS therapy is FDA-approved for the treatment of depression. And given that anxiety and depression go hand in hand, anxiety symptoms may emulate and get better along with the depressive symptoms after TMS.
TMS Appears to Dampen the Overactive, Anxious Right-sided Brain
In depression, TMS functions by stimulating the underactive areas of the brain. However, anxiety is believed to be a process of a misfiring of electrical signals with a constant chatter between different brain regions. Hence, anxious minds have both overactive and hypoactive areas.
Especially noted, are abnormally low levels of activity in the left area of your brain known as the prefrontal cortex. The prefrontal cortex is not only your brain's "executive control" center but also plays a role in regulating your emotions. More importantly, a segment of the prefrontal cortex dubbed as the dorsolateral prefrontal cortex (DLPFC) helps your cognitive reasoning processes overpower your emotional processes.
Hence, an underactive prefrontal cortex will lack the potential to regulate your emotions through cognitive appraisal, putting you at risk of anxiety and depression.
The DLPFC is connected to another almond-shaped brain region referred to as the amygdala (the hub of fear and emotions in your brains).
In people with anxiety, the amygdala classically shows overactivity in response to anxiety cues. That said, it is the hyperactivity of the “right” amygdala that is shown to drive undue and disruptive worrying defining an anxiety disorder.
Because the right side of your brain fuels anxiety, blunting the activity levels in the right hemisphere may help ease anxiety. Thus, applying slow, inhibitory, low-frequency magnetic pulses via TMS to the right side of the brain, could inhibit and calm down the hyperactive circuits of the brain on that side.
At the same time, TMS can also help buffer the activity levels of the DLFPC. Altogether, TMS may help quieten an anxiety-ridden brain.
Nonetheless, there is no standard intervention protocol for the use of TMS in people with anxiety.
How Effective is TMS in Anxiety Disorders?
A 2019 scientific survey compiled about 32 studies to evaluate the effects of rTMS on anxiety. Though this survey suggested the need for more studies to determine the effects of TMS on anxiety, it did reveal the beneficial impact of TMS on anxiety symptoms.
According to this survey, one of the clinical trials conducted on participants with a generalized anxiety disorder (GAD) showed a clinically substantial reduction in anxiety symptoms after receiving 25 rTMS sessions.
Another 2016 study conducted by Dr. Diefenbach and fellows showed improved outcomes in patients with GAD after a 3-month rTMS treatment. Six of nine patients in the active group achieved remission during the 3-month follow-up period.
Patients with anxious depression particularly appear to benefit from rTMS sessions. A 2019 study evaluated and compared the outcomes of 172 patients with comorbid anxiety disorders with patients who did not have comorbid anxiety. At the end of the TMS session, 39.5% of patients showed 50% improvement in their symptoms of depression. In addition, 23.3% of patients with depression and comorbid anxiety achieved remission.
Another condition that often follows anxiety symptoms is Restless Legs Syndrome (RLS). In fact, stress and anxiety are major triggers of RLS. A study done on patients with RLS who received TMS therapy revealed significant improvements in the symptoms of restless legs, anxiety symptoms, and sleep quality.
In light of these studies, TMS seems to serve as a suitable measure to improve anxiety symptoms. With that said, there is still a need for further large sample size studies to prove TMS’s effectiveness in anxiety disorders.
TMS for OCD
OCD is a highly disabling condition. The World Health Organization (WHO) ranks OCD in the top 10 disabling ailments, as it causes a serious impairment in social and occupational relationships as well as daily living.
Why do we need TMS for OCD?
1. First-line Treatments for OCD do not Always Work
Unfortunately, about half of all patients with OCD fail to respond to traditional medications. Moreover, OCD requires using higher doses of these medicines, which comes at the cost of serious side effects, causing patients to stop their treatment. Even in patients who do take their medications as prescribed, it’s seen that there is never a complete relief from symptoms.
Another option commonly employed by practitioners for OCD is behavioral therapy in the form of exposure and response prevention (ERP) and cognitive therapy. ERP involves exposing the patient to the very cues that evoke distressing and obsessive thoughts. That said, patients often feel frustrated after being exposed to distressing cues, resulting in high dropout rates from behavioral therapies.
2. Second-line options for OCD Carry Serious Risks
If drug and behavioral therapies fail, the next step employed by practitioners is a procedure known as ventral capsulotomy. It involves surgically implanting a deep brain stimulator (DBS), which targets the area of the brain linked to OCD. Though this procedure has shown promise in treatment-refractory patients, just like any other surgery, DBS carries serious risks.
In the face of treatment-resistant OCD, there has been a pressing need to develop new, effective, safe, and tolerable therapies to minimize the huge burden of this condition. One of these therapies is TMS or dTMS.
What is dTMS and How is it Different from Conventional TMS?
Up till now, clinical trials using TMS for OCD were being studied with non-deep TMS, which showed limitations in its results because the magnetic pulses only had access to the superficial cortical areas of the brain.
However, the advent of advances in neuroscience in the last few decades has paved the way for a novel third option for treating OCD, called deep transcranial magnetic stimulation, or dTMS.
dTMS therapy is now FDA-approved as an add-on treatment for OCD. The most popular method to apply dTMS in OCD is the Brainsway Method. It uses a lightweight helmet with magnetic pulses generated through a built-in coil known as an H-coil to specifically penetrate the deeper areas of the brain implicated in OCD. Hence, dTMS allows for stimulation of larger brain volume than conventional TMS.
Similar to conventional TMS, dTMS is also an entirely non-invasive therapy and done as an out-patient procedure with virtually no side effects.
How does dTMS work for OCD?
The areas specifically implicated in OCD are the orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC). These areas are located in the frontal lobes (that sit in the very front of the brain) and are responsible for error-detection and emotional, reward, and behavioral regulation.
Research shows that the OFC and ACC:
- are hyperactive at rest in people with OCD compared to healthy patients
- become overly active when symptoms are provoked
- resume their normal activity after successful treatment with either medical or behavioral therapy
Normally, these regions are intimately connected to the basal ganglia — a cluster of nerve cells responsible for movement and regulating emotions and behavior. The basal ganglia receive the input from the cerebral cortex. These signals are then conveyed to another brain region called the thalamus, which then relays this information back to the cortex.
However, hyperactivity in the frontal lobes of OCD patients breaks the communication between the basal ganglia and thalamus. This causes the thalamus to get out of control. This failure of the frontal lobes to inhibit the thalamus is what triggers unrelenting intrusive thoughts and behaviors.
The usage of dTMS in tweaking brain activity in OCD is contingent upon the maladaptive behavior of neurons in these networks. It either excites or suppresses these target regions based on the frequency of magnetic pulses applied.
How Effective is dTMS for OCD?
dTMS therapy has optimized the odds for people with OCD to finally receive treatment that will benefit them.
A 2019 clinical study published in the American Journal of Psychiatry showed a statistically significant (30%) improvement in OCD symptoms in the dTMS group after 6 weeks of daily sessions, as measured by the Yale-Brown Obsessive-Compulsive Scale. The treatment was as effective as the medications available for treating OCD. Nonetheless, dTMS achieved quicker results relative to medical therapy.
This study was a rare one because it entailed provoking OCD symptoms in the participants prior to each treatment session. The idea behind provoking OCD symptoms was to activate the relevant brain circuitry.
Are there any Downsides to TMS for OCD?
Deep TMS is a safe therapy, with minimal to no side effects. As noted in the above study, the only side effect reported by patients was headache, and that too subsided shortly after treatment.
To be successful, TMS, however, requires daily sessions. Because the sessions only last for 15 to 20 minutes on an average, daily commitment isn’t a problem for the majority of patients.
Though OCD is a treatable illness, not all patients respond to the currently available treatments. Even when patients do respond, it is rare to see them completely recovering from the condition.
Thanks to novel treatments like deep TMS that hold more promise for refractory OCD. Being a non-invasive therapy with minimal adverse effects, dTMS is considered a good alternative for people who fail to respond to first- or second-line therapies.
Two companies now offer FDA-cleared TMS devices for the treatment of OCD, namely Brainsway and MagVenture.