The success of pharmacology in the treatment of depression has caused many psychiatrists to overlook a crucial fact: Our brains are as much electrical as they are chemical. Consequently, electrical stimulation of brain centers holds great promise for the treatment of depression. and internationally.
Altering the balance of our neurotransmitters with medications is a proven method of influencing mood, and has led to a multi-billion dollar industry. But changing the chemical soup in our brains remains an indirect method. And SSRIs, the most successful antidepressant medications, are even more indirect, since they don't actually produce the feel-good neurotransmitter serotonin, but merely inhibit its disappearance (reuptake).
As neuroscience has progressed, specific brain circuits involved in stress, anxiety and depression have been identified. At the same time advances in the medical use of electrical and magnetic devices to alleviate pain and other symptoms have led researchers to apply these techniques to the treatment of mental illness. Rather than manipulating neurochemicals in general, these latest brain stimulation treatments use electricity and magnetism to directly target the source of the problem in the brain.
Seven types of electrical and/or magnetic brain stimulation treatments are currently being used or investigated that range from extremely invasive (requiring brain surgery) to completely non-invasive (using magnets outside the head).
- Deep brain stimulation: The most invasive of the brain stimulation techniques, this treatment involves surgically placing a thin wire in the brain, and delivering small currents of electricity directly to areas believed to be responsible for the dysfunction, such as the subgenual cingulate (Cg25) region . A team of Toronto researchers says it has obtained promising early results from a landmark surgical study of the use of deep brain stimulation (DBS) in severely depressed patients who were otherwise resistant to standard types of treatment.
- Vagus nerve stimulation: Currently approved for treating epilepsy, this approach has also been shown to be successful for drug-resistant major depression. This requires a surgical implantation of an electrode wrapped around the vagus nerve in the neck and controlled by a pacemaker. However, the operation does not require brain surgery. The device delivers small doses of electricity to the vagus nerve, which alters the signals it sends to the brain. The manufacturer claims the device is more effective than antidepressants.
- Electroconvulsive therapy: This is an updated and more sophisticated version of traditional shock therapy, with much lower voltages and fewer side effects. Still, this treatment uses electricity applied directly to the brain to induce a seizure under anesthesia. This method is still used, and can still be transformative for people with very severe depression.
- Cranial Electrical Stimulation (CES): A pocket-sized device inputs gentle electrical currents into the brain via electrodes. The intensity is entirely controlled by the user. Approved by the FDA for use in anxiety, depression, and insomnia.
- Repetitive Transcranial Magnetic Stimulation (rTMS): This experimental treatment is very promising for a wide range of depressive ailments.The newest and least invasive type of brain stimulation therapy, this technique uses powerful electromagnets to produce electric currents on surface of brain. Over 20 studies have shown rTMS is effective compared with placebo in relieving severe depression in patients that haven't responded to traditional therapies.
The relatively simple treatment, which delivers brief but intense magnetic pulses to the brain, may be as effective as traditional electroconvulsive therapy in treating severe depression, according to a University of Illinois at Chicago study.
- MRI scans: Recently (03/05), Harvard Medical School released a report claiming successful treatment of depression for patients undergoing Magnetic Resonance Imaging (MRI) scans. MRIs generate electrical and magnetic fields in the brain in the process of imaging soft tissue. Much more research will need to be done to confirm the effectiveness of this method. However, these scans are expensive, and it seems unlikely that these experimental treatments will ever be available except to the most drug resistant patients.
- Neurofeedback: Neurofeedback is actually a form of biofeedback used to train the brain to produce different brain wave activity. As such, it does not directly send electrical energy into the brain. However, it has a marvelous track record in the treatment of stress, anxiety, and depression. Many reports and published studies attest to it's effectiveness with these problems, with established protocols to alleviate symptoms.
What will it take for these alternative treatments to become more widely available? The answer is continued research and clinical studies, physician education, and public acceptance. We will also need a healthcare model that creates a realistic return on investment in equipment and training. The first of these new treatments to successfully pass all those hurdles will likely be transcranial stimulation. Meanwhile, Cranial Electrical Stimulation already has FDA approval, though it is not widely available. Neurofeedback works, and is available in many areas in the U.S.
