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 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.
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.
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.
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.
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.
