Today’s first line of defense against depression is medication and therapy. However, for some people, these treatments are not effective enough. In these cases, what clinicians call treatment-resistant depression, more advanced methods are needed to help patients feel relief. Among these methods is transcranial magnetic stimulation, or TMS for short.
What is TMS?
TMS is based on the theory that altering electrical impulses in the brain diminishes the effects of depression. Neurons– brain cells- relay messages to each other via electrical signals. Sometimes these signals can become disrupted, and as a result, depression develops. Resetting these impulses can only be done through the administration of an outside electrical current. Electroconvulsive therapy (ECT) is the most well-known example of this kind of treatment. However, ECT is time-intensive and presents side effects. Unlike ECT, TMS is non-invasive and has fewer side effects.
TMS uses a large magnetic coil placed on the outside of the head. When turned on, the magnet creates electrical pulses that pass through the skull and into the brain. These pulses increase neuron activity, meaning the neuron begins to fire more consistently than before. TMS is repeated over many sessions, usually lasting six to twelve weeks; the frequency per week is determined by each individual’s physician. Over time, repeated exposure to the magnetic pulses changes the patient’s neuronal activity and decreases, or entirely relieves, their depressive symptoms.
How is TMS delivered?
Even though it has a complicated name, TMS is administered rather simply. TMS is performed by a qualified physician or nurse in either a doctor’s office or hospital. When you arrive, you will be seated and given earplugs. This is because the TMS machine makes clicking noises, much like an MRI machine. The close proximity of the magnet to your ears makes it important to protect your hearing. The doctor will then take specific measurements to find the proper positioning of the magnet and place it above your head.
Before TMS can start, the doctor must find your motor threshold. This is done by delivering small pulses from the magnet and finding the least amount of power it takes to make one of your fingers move. The motor threshold is used to ensure you are receiving the correct dosage of electricity. When the motor threshold has been found, your doctor will lower the magnet into place on the frontal region of your head and turn it on.
You may feel something tapping on your head when TMS is in progress. That sensation is the electrical pulses from the magnet, but it will not hurt. Each session lasts around 30-40 minutes. You will be able to leave immediately after each session. Other alternative treatments may require you to recover at the hospital or office after treatment, but TMS’s non-invasive nature means you can return to daily life immediately after your sessions.
What are the side effects of TMS?
Unlike many other depression treatments, there are few side effects of TMS. The most common side effect is headaches after the first few sessions. These usually go away with time. A rare, but more serious, side effect of TMS is seizures. Your doctor will monitor your health closely to reduce the risk of side effects, but it is always important to talk to your doctor if you begin to feel strange or different after TMS sessions.
