Neuroscience News
March 23, 1998
Magnetism and Depression
New strategies for treating depression are continually sought, partially to improve upon treatments that already exist, such as antidepressants drugs or electroconvulsive therapy (ECT), and partially to accommodate patients for whom these standard treatments offer little relief of depressive symptoms. One hopeful development in the treatment of depression is the use of the experimental procedure, transcranial magnetic stimulation.
Depression is a disorder that effects over 35 million people in the United States. It has been estimated that over one quarter of all people will suffer depression at some point in their lives, and many of these people will have repeated bouts of depression. Because severe forms of depressive illness, such as major depression, can have a dramatic impact one's ability to function at work or in social situations, it is clear that this disorder has serious consequences, not only for the patient, but for those around them as well.
Symptoms of depression can include:
- Persistent sad, anxious, or empty mood
- Feelings of hopelessness, pessimism, guilt, or worthlessness
- Loss of interest or pleasure in hobbies and activities that you once enjoyed, including sex
- Disturbances in sleeping or eating habits accompanied by weight gain or loss.
- Decreased energy. fatigue, and perhaps restlessness and irritability
- Thoughts of death or suicide, suicide attempts
- Difficulty concentrating, remembering, making decisions
These symptoms can be debilitating, for example in major depression, where patients are typically unable to function at all because of their severity. Fortunately, most people who suffer these symptoms can be aided by standard treatments. However, as many as 20% of people with sever forms of depression do not find relief from standard treatments. A new form of treatment, transcranial magnetic stimulation, may offer relief for some of these patients.
A recent study from Emory University [3, see also the story on CNN] contributes to a growing body of evidence [1, 2, 4, 5, 6] that suggest many patients for whom drug therapies prove ineffective, can find relief through transcranial magnetic stimulation. In this procedure, electromagnets are used to modify the electrical activity of the cerebral cortex. It is not understood exactly how this works to alleviate depressive symptoms, but it is thought to stimulate a portion of the left frontal cortex, which in depressed patients seems to have reduced function [5]. The treatment is effective in about half of patients that are resistant to drug therapies. Additionally, it seems to lack serious side-effects (although some patients report headache), and is therefore considered safe. In addition to helping patients who would otherwise continue to suffer from symptoms, it is hoped that further investigations into this and other treatments can offer insights into the mechanisms of their action and furthermore, into the pathology of depression itself.
More links to about depression can be found on my Diseases and Disorders pages.
Bibliography:
[1] Abarbanel JM, Lemberg T, Yaroslavski U, Grisaru N, Belmaker RH, 1996.
Electrophysiological responses to transcranial magnetic stimulation in depression and schizophrenia. Biol. Psychiatry 15:148-150.
[2] Conca A, Koppi S, Konig P, Swoboda E, Krecke N, 1996.
Transcranial magnetic stimulation: a novel antidepressive strategy? Neuropsychobiology 34:204-207.
[3] Epstein CM, Figiel GS, McDonald WM, et al., 1998.
Rapid rate transcranial magnetic stimulation in young and middle-aged refractory depressed patients. Psychiatric Ann. 28:36-39.
[4] George MS, Wassermann EM, Kimbrell TA, Little JT, et al., 1997.
Mood improvement following daily left prefrontal repetitive transcranial magnetic stimulation in patients with depression: a placebo-controlled crossover trial. Am. J. Psychiatry 154:1752-1756.
[5] Kirkcaldie MT, Pridmore SA, Pascual-Leone A, 1997.
Transcranial magnetic stimulation as therapy for depression and other disorders. Aust. N. Z. J. Psychiatry 31:264-272.
[6] Pascual-Leone A, Rubio B, Pallardo F, Catala MD, 1996.
Rapid-rate transcranial magnetic stimulation of left dorsolateral prefrontal cortex in drug-resistant depression. Lancet 348:233-237.