Dr. Kira Stein, an expert on psychiatric treatment, talks with author Andy Behrman about treatment-resistant depression and the workings of transcranial magnetic stimulation (TMS), a relatively new therapy for that condition.
Treatment-Resistant DepressionAB: What exactly is treatment-resistant depression?
KS: When one is correctly diagnosed with clinical depression, participates in psychotherapy, takes medication at a proper dose for a sufficient period of time (usually 4 to 6 weeks) - and still feels little to no relief - he or she is considered to be suffering from "treatment-resistant depression." Approximately 15% of depressed patients are treatment-resistant and continue to suffer from debilitating depression.
The term "treatment resistant" is misleading because it suggests an inability to respond to any treatment. The truth is that by the time a patient is first designated as "treatment resistant," many untried treatment options can still be employed - there is still hope.
AB: What are the consequences of treatment-resistant depression?
KS: With treatment-resistant depression, the impact can be severe. In addition to the risk of suicide, ongoing depression increases the risk of mortality from other medical illnesses such as diabetes, heart disease, stroke, cancer, and substance abuse.
Depression has very serious repercussions that extend beyond the health and well-being of patients themselves. Persistent mental illness can lead to a loss of personal and work productivity, unemployment, family estrangement, and increased costs for caregivers and employers. Clinical depression has a significant negative impact on society at large, costing the U.S. economy tens of billions of dollars annually in lost productivity and medical expenses.
AB: I understand that transcranial magnetic stimulation, or TMS, is a relatively new treatment that you are using to address clinical depression. At what point in a patient's depression do you employ TMS? Is TMS a good therapy for treatment-resistant depression?
KS: TMS is an excellent option for patients who have not responded to their first medication, because research shows that TMS is considerably more effective than trying a second medication - with less risk of side effects. In fact, TMS is FDA-approved for the treatment of a major depressive episode that has failed to adequately respond to a first medication.
AB: How does TMS work?
KS: The standard TMS treatment for depression involves resting a small MRI-strength magnet on the area of scalp overlying a part of the brain called the left dorsolateral prefrontal cortex, which is known to be underactive in depression.
Magnetic pulses emanating from the TMS machine induce tiny electrical changes in brain cells (neurons) that, when effective, normalize neurotransmitter and receptor levels, as well as connections between the frontal lobe and other brain areas.
Research shows that, when stimulated, frontal lobe neurons release the neurochemicals glutamate and dopamine into frontal lobe synapses that connect to other brain cells in other parts of the brain. TMS also appears to affect serotonin receptors in the frontal lobe and deeper brain structures. These and other changes in the brain are associated with improved mood.
AB: Is there ever a time when you choose to recommend a second or third trial of medication over TMS?
KS: Decisions about patient care need to be made on a case-by-case basis. When I feel it is clear that a patient is responding partially to a medication, and that his or her specific residual symptoms would best be addressed with a specific pharmacological treatment or hormonal therapy, I will opt for another trial of medication rather than TMS.
AB: Do you think there is a possibility that TMS will become a first line treatment in the near future?
KS: Since TMS was first FDA-approved for treatment-resistant depression in 2008, with ongoing real world clinical experience with TMS, specialists are learning even better ways to employ TMS, making it increasingly more effective. As the field of TMS refines further over time, I believe it will one day become a first line option for the treatment of depression.
NOTE: Dr. Stein's interview responses are for general information purposes only and are not intended to be professional medical, psychological, or legal advice for any specific situation or individual. This information is intended for individuals and their families to use in consultation with a qualified healthcare professional. Dr. Stein does not warrant or make any representations, and disclaims any and all liability, concerning any treatment or action by any individual who has made decisions based on information from this interview.