Safety & Side Effects of TMS Part 4:Contraindications for TMS Therapy

---

---

While Transcranial Magnetic Stimulation (TMS) is a remarkably safe and well-tolerated treatment for many people, not everyone is a candidate. Just like any medical procedure, there are specific medical conditions, risk factors, or implanted devices that may make TMS unsafe for certain individuals. These are called contraindications—situations where the treatment should be avoided because the risks may outweigh the benefits.

Understanding these contraindications is key to patient safety and helps providers make informed decisions before beginning treatment.

Metal in or Near the Head

The most widely recognized contraindication for TMS is the presence of metal in or near the head, excluding the mouth (dental fillings, crowns, and braces are all fine). Because TMS works by producing powerful magnetic fields, there’s a risk that certain metals could heat up, shift position, or interfere with the electromagnetic pulses, especially if they’re implanted close to the coil’s target area.

However, not all metals pose a danger.

The concern lies specifically with ferromagnetic metals—these are metals that can be attracted or moved by a magnetic field. If a patient has ferromagnetic materials in the skull, brain, or face (such as an old bullet fragment or some types of surgical clips), those could respond to the magnetic pulses and pose a safety risk.

But non-ferromagnetic metals, such as titanium or medical-grade stainless steel, are typically not attracted to magnets and are generally safe for use with TMS. For example:

• Titanium plates, screws, or mesh in the skull from prior surgeries are usually non-ferromagnetic.
• Cochlear implants, deep brain stimulators, or vagus nerve stimulators, on the other hand, often contain electronic or magnetic components that are not safe, even if they’re not ferromagnetic.

To determine whether an implant is safe, clinics often request:

• Surgical documentation identifying the exact materials used
• Manufacturer safety data sheets
• Or consultation with a neurologist, neurosurgeon, or the implanting physician

This distinction is critical because some patients who were previously told they “have metal in the head” may actually still be good candidates for TMS if the implant is non-ferromagnetic and well outside the stimulation zone.

As a rule of thumb, if there’s any metal or device implanted above the shoulders, it needs to be reviewed and cleared by the provider team before starting treatment.

History of Seizures or Epilepsy

Although TMS has an incredibly low risk of causing seizures, patients with a history of epilepsy or unprovoked seizures are typically excluded from standard TMS treatment. That’s because their brains are more prone to irregular electrical activity, and TMS could theoretically increase the risk—even if the condition has been dormant for years.

In some rare, carefully monitored cases, TMS may be considered with neurologist supervision, but this is the exception, not the rule.

Active Substance Use

People who are currently using drugs or alcohol—especially stimulants or sedatives—may not be good candidates for TMS. As discussed earlier, substances like cocaine, methamphetamine, benzodiazepines, or alcohol withdrawal can significantly increase seizure risk and disrupt brain chemistry.

Most clinics will postpone treatment until a person is stable and free of recent substance use. This protects both the patient and the long-term success of the therapy.

Unstable Bipolar Disorder

TMS is FDA-approved for unipolar (non-bipolar) depression, but it has also been used off-label to treat bipolar depression—specifically the depressive phase. However, TMS is not appropriate for patients in a manic or mixed mood state, as it may worsen symptoms or trigger instability.

Before starting treatment, providers typically screen for:

• Past manic episodes
• Recent rapid mood swings
• Inconsistent medication use for bipolar disorder

If TMS is still considered, it may be paired with a mood stabilizer to lower the risk of triggering hypomania or mania during treatment.

Certain Neurological or Medical Conditions

TMS is generally well tolerated, but individuals with active neurological diseases, such as multiple sclerosis with seizure involvement or progressive neurodegenerative conditions like ALS, may not be ideal candidates. Additionally, people with uncontrolled cardiac conditions, recent strokes, or implanted pacemakers (depending on location and type) may require extra screening.

Each clinic will evaluate medical history thoroughly to determine whether TMS is safe on a case-by-case basis.

Psychological Contraindications

TMS may not be a good fit for individuals who are currently:

• Experiencing severe suicidal ideation or recent suicide attempts
• Unable to sit still or tolerate the setup for treatment (which typically requires stillness for 20–30 minutes)
• Experiencing active psychosis (e.g., hallucinations or delusions not related to depression or OCD)

These situations may require more immediate psychiatric stabilization before starting TMS.

Final Thoughts

Contraindications to TMS are rare, but they matter. Most people who are turned away from TMS are not rejected permanently—they may simply need more time to stabilize, adjust medications, or finish treatment for another condition before becoming eligible. With proper screening, TMS continues to be one of the safest and most promising tools in modern mental health care.

Sources

1. Rossi, S., Hallett, M., Rossini, P. M., & Pascual-Leone, A. (2009). Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research. Clinical Neurophysiology, 120(12), 2008–2039. https://doi.org/10.1016/j.clinph.2009.08.016
2. McClintock, S. M., Reti, I. M., Carpenter, L. L., et al. (2018). Consensus recommendations for the clinical application of TMS for the treatment of depression. Journal of Clinical Psychiatry, 79(1), 16cs10905. https://doi.org/10.4088/JCP.16cs10905
3. George, M. S., & Aston-Jones, G. (2010). Noninvasive techniques for probing neurocircuitry: TMS and beyond. Biological Psychiatry, 68(4), 291–293. https://pubmed.ncbi.nlm.nih.gov/19693003/
4. Lefaucheur, J. P., André-Obadia, N., Antal, A., et al. (2014). Evidence-based guidelines on the therapeutic use of rTMS. Clinical Neurophysiology, 125(11), 2150–2206. https://doi.org/10.1016/j.clinph.2014.05.021

Locations

Choose the office that’s most convenient for you. Our Chesterfield and Richmond Heights locations are here to provide accessible, patient-focused care in a welcoming and professional environment.

CHESTERFIELD
112 Chesterfield Commons East Rd.
Chesterfield, MO 63005
314-697-4867

RICHMOND HEIGHTS
1505 S Big Bend Blvd,
Richmond Heights, MO 63117
314-384-1006