Brain stimulation therapies are a group of treatments for depression that involve procedures to stimulate the brain with electricity, magnets or implanted devices. In general, the brain stimulation therapies are only used in cases of severe depression after people have not had success with psychotherapy and medications. Brain stimulation therapies or similar procedures are often depicted in books and movies as extreme forms of treatment or punishment, for example in the movie One Flew Over the Cuckoo’s News. Therefore it can be easy to get the wrong idea about how they are used and what the entail. However, these treatments have been significantly refined over the years. Electroconvulsive therapy is by far the most widely studied of the brain stimulation therapies. Other types of stimulation treatments described here have been developed more recently and are still being evaluated for their effectiveness and long term effects. However, overall, they are in wide use, are generally safe, and are not used solely in inpatient psychiatric hospitals.
Electroconvulsive Therapy (ECT)
ECT is the oldest of the brain stimulation therapies. It is typically used in cases of severe depression and/or suicidality, usually when other treatments have not worked. ECT is one of the more potent antidepressant treatments identified. However, it’s effects are relatively short lasting, and so it is usually used in combination with medication and/or psychotherapy. In ECT, electrodes are placed at precise locations on the head in order to pass brief pulses of electricity through the brain, which trigger a seizure. The procedure is conducted under general anesthesia. A typical ECT treatment may involve receiving ECT 3 times per week for 2-4 weeks. Years ago, ECT was a relatively imprecise procedure and people who received ECT could experience significant muscle soreness and memory loss. Muscle relaxants are administered ahead of time to prevent body muscles from contracting, which decreases muscle soreness. Memory loss can still occur but is usually mild and constrained to the time immediately around receiving the ECT. The most common side effects are headache, upset stomach and mild muscle aches. It is usually conducted as an outpatient procedure meaning a person does not need to spend the night in the hospital.
Vagus Nerve Stimulation (VNS)
VNS was originally developed as a treatment for epilepsy (seizure disorder). However, it was discovered to have positive impacts on mood, which led some to wonder about its potential as antidepressant treatment. In 2005, the FDA approved it as a treatment for depression when multiple attempts with other treatments have not worked. In VNS, a device is implanted under the skin in the chest and neck to send electrical pulses through the left vagus nerve, which runs from the base of the brain down through the neck to the chest and stomach. The device sends periodic pulses of electricity, while the person goes about normal life. Frequently a person does not feel anything when the pulses are occurring although it may stimulate a cough or hoarse voice. Other potential side effects are rare but can include neck pain, infection at the site of the implant, difficulty swallowing, and breathing problems, especially during exercise.
Repetitive Transcranial Magnetic Stimulation (rTMS)
In rTMS, magnets are attached to different places on the scalp in order to activate specific regions of the brain. A typical rTMS sessions lasts 30-60 minutes and is conducted while a person is awake. rTMS does not tend to cause memory loss although mild headache and brief lightheadedness can occur. It has been studied as a treatment for depression since the 1980’s and was approved by the FDA as a treatment for depression in 2008. Although some studies have shown it to be effective for treating depression, other research has shown no benefit. This may be in part because understanding the best way to position magnets and the optimal treatment frequency is still being refined. Thus, rTMS is still considered somewhat experimental and is usually only considered as a treatment option for people who have not responded to at least one other more established form of depression treatment.
Deep Brain Stimulation (DBS)
In DBS, devices are surgically implanted deep within the brain in order to activate specific brain regions with electrical impulses. Stimulation is continuous and is personalized based on a person’s early responses to the electrical impulses. DBS is considered the most experimental of the Brain Stimulation Therapies for depression. Because it is still highly experimental and because implanting the electrodes requires brain surgery, which brings significant risks, DBS is only considered for people with severe, chronic depression that has not been helped by psychotherapy, medication or ECT. Although this is still a very new and experimental procedure, early research is promising with many patients reporting a near immediate improvement in depressive symptoms.