Transcranial Magnetic Stimulation (TMS) is gaining recognition as a non-invasive treatment option for various mental health conditions. This innovative approach uses magnetic fields to stimulate nerve cells in specific brain regions. Its relevance to conditions like bipolar disorder is a subject of ongoing exploration and development.
What is Transcranial Magnetic Stimulation
TMS operates on the principle of electromagnetic induction. An electromagnetic coil is placed on the scalp, which generates pulsed magnetic fields. These fields pass through the skull and induce small electrical currents in the targeted brain tissue. This non-invasive method influences brain activity by stimulating nerve cells and altering their function.
The magnetic pulses can either increase or decrease the excitability of neurons, depending on the frequency and pattern of stimulation. This modulation of neural activity is thought to produce therapeutic effects. Unlike other brain stimulation techniques, TMS does not require anesthesia or sedation, making it a well-tolerated outpatient procedure.
How TMS Targets Bipolar Symptoms
TMS aims to modulate neural circuits, particularly within the prefrontal cortex, a brain region implicated in mood regulation and often showing dysfunction in bipolar disorder. For depressive episodes in bipolar disorder, TMS typically targets the left dorsolateral prefrontal cortex (DLPFC), an area that often exhibits reduced activity. By stimulating this region, TMS seeks to normalize brain activity, potentially alleviating depressive symptoms.
While TMS is widely approved by the U.S. Food and Drug Administration (FDA) for major depressive disorder, its application for bipolar depression has a “breakthrough device designation,” as of 2020. This designation expedites the review process, acknowledging its potential for more effective treatment for conditions like bipolar depression. This means that while it is not yet fully FDA-approved for bipolar disorder, the device is considered medically safe for use and sale.
The rationale behind targeting specific brain regions for bipolar symptom relief stems from observations of altered neural activity in individuals with the condition. Studies suggest that stimulating the left prefrontal cortex can be effective in treating bipolar depression. Conversely, some research indicates that stimulating or inhibiting the right prefrontal cortex might have an anti-manic effect, though findings in this area are still being refined.
The TMS Treatment Journey
A typical TMS session for bipolar disorder involves the patient sitting comfortably, often in a reclined chair. A medical professional positions the magnetic coil against the patient’s scalp, usually near the forehead over the prefrontal cortex. During the session, patients commonly experience a tapping or clicking sensation on their scalp, which is generally mild. Some individuals might also feel mild headaches or scalp discomfort, especially during the initial sessions, but these are typically temporary.
Individual TMS sessions typically last between 20 to 60 minutes, though newer protocols like intermittent theta burst stimulation (iTBS) can be as short as 3 to 5 minutes. A standard course of treatment for depression usually involves daily sessions, five days a week, for a period of four to six weeks. Patients remain awake and alert throughout the procedure and can typically resume their daily activities immediately after each session.
Potential side effects of TMS are generally mild and temporary. These include scalp discomfort, headaches, temporary mood swings, increased anxiety, or mild fatigue. While very rare, seizures are a potential serious side effect, occurring in less than 0.1% of patients. Ear protection is provided during treatment to mitigate any hearing sensitivity from the clicking sounds.
Is TMS Right for Bipolar Disorder
Individuals considering TMS for bipolar disorder should undergo a comprehensive evaluation by a qualified mental health professional. This assessment helps determine if TMS is an appropriate and safe option, especially since it is typically considered when other treatments, such as medication and psychotherapy, have not provided sufficient relief. TMS is often used as an adjunctive therapy, meaning it complements other treatments rather than replacing them entirely.
Certain factors may make an individual ineligible for TMS. Contraindications include the presence of metal implants or electronic devices in or near the head, such as pacemakers, aneurysm clips, or cochlear implants, due to the magnetic fields. A history of seizures or epilepsy is also a contraindication, as TMS can lower the seizure threshold. While TMS has shown promise for bipolar depression, there is a small risk of inducing a manic episode in individuals with bipolar disorder, which necessitates careful monitoring during treatment.