For those who suffer debilitating depression, stimulating the brain can bring desperately needed relief, new research shows. The study findings suggest that this type of therapy should be considered as an alternative or additional treatment for the toughest cases of the mood disorder.
Depression is typically treated with drugs and counseling, but these methods don’t work for every patient and some suffer unpleasant side effects from drugs, the study authors noted.
Enter non-surgical brain stimulation techniques, which use electrical currents or magnetic fields to alter brain activity. Medical guidelines support the use of these techniques, the researchers said, but they tend to be used too little and too late, and research into their effectiveness has been limited.
In the latest study, published March 27 in the BMJ, the investigators analyzed the results of 113 clinical trials involving over 6,700 patients, average age 48, who had major depression or bipolar depression, and received either brain stimulation or sham therapy.
The treatments included electroconvulsive therapy, transcranial magnetic stimulation, or TMS, magnetic seizure therapy, and transcranial direct current stimulation.
All of the treatments were more effective than the sham therapy by all measures, according to lead researcher Julian Mutz, of the Institute of Psychiatry, Psychology & Neuroscience at King’s College London.
Commenting on the report, Dr. Bryan Bruno said, “Although this study does not look carefully at the long-term benefits of these treatments, it reminds us that these treatments should be considered more often and earlier by physicians to treat their patients with depression.” Bruno is a psychiatrist at Lenox Hill Hospital in New York City, and was not involved with the new study.
“TMS, in particular, is not only effective, but also very safe and well-tolerated by patients,” Bruno added.
It’s not clear how brain stimulation helps treat depression, the study authors said in a journal news release. In the case of TMS, it’s believed to change activity in areas of the brain that are underactive or overactive in depression.
The study also found that patients who received brain stimulation were no more likely to halt treatment than those who received the sham therapy.
The findings “will inform clinicians, patients and health care providers on the relative merits of multiple non-surgical brain stimulation techniques,” Mutz and his colleagues concluded.
Brain Stimulation Therapies
Brain stimulation therapies can play a role in treating certain mental disorders. Brain stimulation therapies involve activating or inhibiting the brain directly with electricity. The electricity can be given directly by electrodes implanted in the brain, or noninvasively through electrodes placed on the scalp. The electricity can also be induced by using magnetic fields applied to the head. While these types of therapies are less frequently used than medication and psychotherapies, they hold promise for treating certain mental disorders that do not respond to other treatments.
Electroconvulsive therapy is the best studied brain stimulation therapy and has the longest history of use. Other stimulation therapies discussed here are newer, and in some cases still experimental methods. These include:
- vagus nerve stimulation (VNS)
- repetitive transcranial magnetic stimulation (rTMS)
- magnetic seizure therapy (MST)
- deep brain stimulation (DBS)
A treatment plan may also include medication and psychotherapy. Choosing the right treatment plan should be based on a person’s individual needs and medical situation, and under a doctor’s care.
artist depiction of electroconvulsive therapyElectroconvulsive therapy (ECT) uses an electric current to treat serious mental disorders. This type of therapy is usually considered only if a patient’s illness has not improved after other treatments (such as antidepressant medication or psychotherapy) are tried, or in cases where rapid response is needed (as in the case of suicide risk and catatonia, for example).
Vagus Nerve Stimulation
artist depiction of vagus nerve stimulationVagus nerve stimulation (VNS) works through a device implanted under the skin that sends electrical pulses through the left vagus nerve, half of a prominent pair of nerves that run from the brainstem through the neck and down to each side of the chest and abdomen. The vagus nerves carry messages from the brain to the body’s major organs (e.g. heart, lungs and intestines) and to areas of the brain that control mood, sleep, and other functions.
Repetitive Transcranial Magnetic Stimulation
artist depiction of repetitive transcranial magnetic stimulationRepetitive transcranial magnetic stimulation (rTMS) uses a magnet to activate the brain. First developed in 1985, rTMS has been studied as a treatment for depression, psychosis, anxiety, and other disorders.
Unlike ECT, in which electrical stimulation is more generalized, rTMS can be targeted to a specific site in the brain. Scientists believe that focusing on a specific site in the brain reduces the chance for the types of side effects associated with ECT. But opinions vary as to what site is best.
Magnetic Seizure Therapy
Magnetic seizure therapy (MST) borrows certain aspects from both ECT and rTMS. Like rTMS, MST uses magnetic pulses instead of electricity to stimulate a precise target in the brain. However, unlike rTMS, MST aims to induce a seizure like ECT. So the pulses are given at a higher frequency than that used in rTMS. Therefore, like ECT, the patient must be anesthetized and given a muscle relaxant to prevent movement. The goal of MST is to retain the effectiveness of ECT while reducing its cognitive side effects.
MST is in the early stages of testing for mental disorders, but initial results are promising. A recent review article that examined the evidence from eight clinical studies found that MST triggered remission from major depression or bipolar disorder in 30-40% of individuals.
Deep Brain Stimulation
artist depiction of deep brain stimulationDeep brain stimulation (DBS) was first developed as a treatment for Parkinson’s disease to reduce tremor, stiffness, walking problems and uncontrollable movements. In DBS, a pair of electrodes is implanted in the brain and controlled by a generator that is implanted in the chest. Stimulation is continuous and its frequency and level are customized to the individual.
DBS has been studied as a treatment for depression or obsessive compulsive disorder (OCD). Currently, there is a Humanitarian Device Exemption for the use of DBS to treat OCD, but its use in depression remains only on an experimental basis. A review of all 22 published studies testing DBS for depression found that only three of them were of high quality because they not only had a treatment group but also a control group which did not receive DBS. The review found that across the studies, 40-50% of people showed receiving DBS greater than 50% improvement.