Transcranial magnetic stimulation or TMS is similar to ECT but uses electromagnetic pulses to generate electrical current in specific regions of the brain that are known to modulate mood. TMS is less likely to cause side effects and has thus been proposed as a possible alternative therapy for those suffering from treatment-resistant depression. (You can read more details about TMS here.)
TMS, if effective, would be an ideal treatment for women who develop depressive symptoms during pregnancy in that there would be no exposure to medications. Findings presented in Athens, Greece at the 12th World Congress of Biological Psychiatry demonstrate that TMS may be a useful alternative for pregnant women with depression.
The study included women with major depressive disorder (MDD) who were treated with active TMS (n=12) and sham TMS (n=10). All women were from 14 to 34 weeks’ gestation.
Women received 20 sessions of right-sided TMS to the dorsolateral prefrontal cortex at a dose of 1 Hz in a 15-minute train at 100% motor threshold (900 pulses/session) or the same number of sessions of sham TMS.
Nine of the 12 women (75%) who received active TMS responded to treatment at the end of the 20 sessions, compared to 5 of 10 women (50%) who received sham TMS. The researchers noted that this high placebo rate may be due to the fact that the sham TMS used a TENS machine, which delivers low-level electrical stimulation and may have had some beneficial effect.
We still need to learn more about the use of TMS in pregnant women with depression. Commenting on these findings, Dr. Meir Steiner commented that for women with moderate to severe depression, antidepressants and ECT are the preferred treatment.We must be cautious here. Although TMS may be an attractive option for women who wish to avoid taking antidepressants during pregnnacy, we do not know if TMS is as effective as antidepressants. No studies have assessed the effectiveness of TMS in women with more severe depression. Nor can we assume that, if a woman has been depression-free while taking an antidepressant, she will have the same response to TMS. But there are women who do not feel comfortable taking antidepressants during pregnancy, and for these women, especially if they have less severe illness, TMS may be a more tolerable option.
Ruta Nonacs, MD PhD
TMS Potential Alternative to Antidepressants in Pregnancy (Medscape – free subscription)