A Massachusetts guide explains that outpatient TMS for depression may cause temporary scalp discomfort or headaches, requires screening, and carries a rare seizure risk.
TMS Side Effects and Safety: A Massachusetts Patient Guide
Transcranial magnetic stimulation (TMS) is a non-invasive treatment that uses magnetic pulses to stimulate areas of the brain involved in mood. It is most often discussed for depression, particularly when other treatments have not provided enough relief or have caused difficult side effects.
TMS was cleared by the FDA for major depressive disorder in 2008, and for depression with comorbid anxiety in 2021. Treatment is usually delivered in an outpatient clinic. A standard course commonly involves about 36 weekday sessions over six to nine weeks, although the exact schedule can vary.
Like any medical treatment, TMS has possible side effects and safety considerations. A proper assessment before treatment is important. Your clinician should review your medical history, current medicines and any implanted devices before deciding whether TMS is suitable for you.
Common side effects during TMS
The most commonly reported side effects are scalp discomfort and headache.
During a session, the treatment coil is placed against the scalp. You may feel tapping, clicking or a repeated knocking sensation. Some people find this uncomfortable at first, especially while the clinician is finding the treatment position and adjusting the intensity. The sensation is usually limited to the time the pulses are being delivered.
A mild headache can occur during or after a session. For many people, this is temporary and becomes less noticeable as they become used to treatment. Let the TMS team know if you develop a headache, scalp pain or any other discomfort. They may be able to check the coil position, adjust aspects of the session or discuss appropriate ways to manage symptoms.
Other practical points to know include:
- TMS does not involve surgery or anaesthetic.
- You remain awake and can generally return to usual activities after a session.
- The machine makes a loud clicking sound, so hearing protection is normally used.
- Tell the clinician if the treatment feels painful, rather than trying to tolerate it without saying anything.
Side effects should be discussed openly. A clinic can only respond to what it knows, and early discussion may help make treatment more comfortable.
The rare risk of seizure
Seizure is a rare but important potential risk of TMS. The risk is one reason that TMS should be prescribed and delivered by trained clinicians using appropriate safety procedures.
Before treatment begins, the clinician will ask questions intended to identify factors that could affect seizure risk. These may include a personal history of seizures, certain neurological conditions, recent changes in medicines, heavy alcohol use or withdrawal, and significant sleep deprivation. This does not necessarily mean that every person with one of these factors cannot have TMS. It means the treating team needs a full picture and may need to decide whether treatment is appropriate or whether additional precautions are needed.
You should contact the clinic promptly if there is a significant change in your health while you are having a course of TMS. This includes a seizure, a new neurological symptom, a serious head injury, a major change in sleep, or a change to prescribed medicines.
Implants, metal and other contraindications
Because TMS uses a magnetic field, metal and electronic implants are important safety considerations. Some implants or metal near the head may mean TMS is not suitable, while others may require specialist review.
Do not assume that a previous operation, dental work or implanted device is automatically safe or automatically disqualifying. Instead, tell the clinician exactly what you have. If possible, bring information about the device, including the name of the implant, when it was fitted and the clinician or hospital responsible for it.
Items to mention include:
- Metal plates, clips, screws or fragments in or near the head
- Aneurysm clips
- Cochlear implants or other hearing implants
- Implanted stimulators or electronic devices
- A pacemaker or other cardiac device
- Previous brain surgery
- Retained metal following an injury
- Dental work, braces or implants
Ordinary dental fillings are not usually the same issue as metal implanted in or near the skull, but they should still be mentioned during screening. The TMS provider can determine whether more information is needed.
It is especially important to tell the team about any metal fragment from an accident, workplace injury or military service, including fragments that may not have caused ongoing symptoms.
What to tell your TMS clinician
A thorough assessment is a key part of safe treatment. Be ready to discuss your physical health as well as your mental health. It can help to write down your medicines and medical history before the first appointment.
Tell the clinician about:
- Any past seizure, fainting episode, epilepsy diagnosis or unexplained loss of consciousness
- Head injury, concussion, stroke or neurological condition
- Brain surgery or any operation involving the head, ears or neck
- Metal or implanted medical devices anywhere in the body
- All prescription medicines, over-the-counter medicines, supplements and recreational drugs
- Recent medicine changes, including changes in dose
- Alcohol use, especially if you have recently reduced or stopped heavy use
- Sleep problems or major sleep loss
- Pregnancy, plans for pregnancy or breastfeeding
- Hearing difficulties or hearing devices
- New symptoms that develop during the course of treatment
Do not stop prescribed medicines simply because you are starting TMS, unless the clinician responsible for your care advises you to do so. Similarly, do not make changes to alcohol, drug or supplement use without discussing this honestly with the treatment team. Accurate information helps them assess safety properly.
If you see more than one healthcare professional, make sure your TMS clinician knows who prescribes your medicines. This is particularly useful if a GP, psychiatrist, neurologist or another specialist makes a change during your TMS course.
Questions to ask before starting
It is reasonable to ask a prospective TMS clinic how it approaches safety. You may wish to ask:
- What screening will be completed before treatment?
- Which implants or medical conditions could affect eligibility?
- How will the team review my current medicines?
- What should I do if I develop a headache or scalp discomfort?
- Who should I contact outside my appointment time if I have a concern?
- What happens if my health or medication changes during treatment?
- How will progress, side effects and treatment response be monitored?
A reputable clinical discussion should leave space for your questions and should include a clear explanation of potential benefits, limitations and risks.
Finding TMS care in Massachusetts
TMS Therapy Massachusetts lists 146 published clinics across the state directory. Listings include clinics in Boston, Worcester, Attleboro, Holyoke, Newton, Framingham, Andover, Springfield, Woburn, Wellesley, West Springfield and Waltham, among other Massachusetts locations.
When comparing clinics, consider practical issues as well as clinical suitability. A standard TMS course usually requires frequent weekday attendance, so travel time, appointment availability and continuity of care may matter. You can also ask clinics whether they work with your insurance and what information they need for a coverage check.
Insurance carriers commonly seen in Massachusetts include Blue Cross Blue Shield of Massachusetts, Harvard Pilgrim Health Care, Tufts Health Plan, Mass General Brigham Health Plan, Fallon Health, UnitedHealthcare, MassHealth and Medicare. Coverage, eligibility requirements and out-of-pocket costs can vary by plan and individual circumstances, so confirm details directly with both the clinic and your insurer.
Getting help in Massachusetts
Visit the TMS Therapy Massachusetts clinic listings to explore local options, read the insurance guide for coverage questions, or use the contact page for help navigating the directory.
This is educational information, not medical advice.
This page is informational and is not medical advice.