Could electrical brain stimulation replace medications for depressed pregnant women?
Question: My daughter suffers from depression and has regularly relied on antidepressant medications to keep on an even keel. She recently got married and wants to start a family. But she is worried about taking drugs while pregnant. How worried should she be?
Answer: Many women with this common mood disorder share your daughter’s concerns. In recent years, numerous studies have tried to clarify the effects that antidepressants might have on a developing fetus.
Overall, “we don’t see a lot of signals for a significant increase in problematic outcomes for babies,” says Dr. Simone Vigod, chief of psychiatry at Women’s College Hospital in Toronto.
But that doesn’t mean antidepressants pose zero risks, she adds. For instance, some research suggests the drugs may slightly elevate the chances of having certain heart malformations in the baby. They might also boost the odds of a pre-term delivery and reduced birth weight. As well, some newborns experience “neonatal adaptation syndrome” – a temporary period of increased irritability as the drug is cleared from the infant’s body.
Although the risks of serious complications are considered to be relatively small, many women still “feel terribly guilty” taking a medication that could potentially harm their child, says Dr. Vigod.
Yet, untreated depression can also cause problems. “A pregnant woman who is severely depressed may not be taking proper care of herself,” explains Dr. Sophie Grigoriadis, head of the Women’s Mood and Anxiety Clinic at Sunnybrook Health Sciences Centre in Toronto.
“She might not be getting adequate nutrition. She may be engaging in behaviours – like smoking or using certain substances – that could have adverse effects on the baby.”
To further complicate matters, access to psychotherapy – a potential alternative to medication – is limited in Canada for a wide variety of reasons.
So, there is a real need for new therapies that pregnant women find acceptable, says Dr. Grigoriadis.
Fortunately, promising research suggests one option might be a relatively simple treatment that delivers an electrical stimulus to the brain.
The treatment is known as transcranial direct current stimulation or tDCS for short. A compact battery-powered device – which can fit in the palm of your hand – provides current to electrodes that are strategically placed on the scalp. In particular, the painless current is directed to a region of the brain called the dorsolateral prefrontal cortex which plays a role in depression.
Previous research indicates that tDCS might provide an effective way of treating some cases of depression. And, in fact, electrical stimulation is increasingly being studied for numerous brain disorders.
“Because the tissues in our brain communicate via electrical signals, the direct electrical current can change what is happening in the brain,” explains Dr. Daniel Blumberger, co-director of the Temerty Centre for Therapeutic Brain Intervention at the Centre for Addiction and Mental Health in Toronto.
“It can promote the brain to change. We think tDCS tips the (brain) circuits into not having depressed patterns of thinking.”
Buoyed by encouraging results from earlier studies, a team of Toronto researchers – led by Dr. Vigod – recently conducted a trial that included 16 women who were followed during their pregnancy and up to a month after delivery.
Half of them received 30 minutes of stimulation five days a week for a period of three weeks, while the others got a placebo or sham treatment which lacked the full duration of current.
The women, who chose not to take antidepressants, were closely monitored in a hospital clinic while they received the real or sham treatment. The study suggested that tDCS has no apparent negative impact on the developing fetus. It also indicated the therapy improves mood.
“Almost all the women in the tDCS group didn’t have symptoms (of depression) one month postpartum, while almost all the women in the sham group did have symptoms,” says Dr. Vigod.
Now the researchers are planning to do a much larger trial and hope to recruit 150 women who will be followed for a year after they give birth to help determine the longer-term effects of tDCS on mother and child.
The pregnant women will be instructed on how to use the highly portable devices in their own homes for the three-week treatment period, thereby eliminating time-consuming trips to a medical clinic.
“Ideally, women want something that is readily available and easy to use,” says Dr. Grigoriadis.
The researchers don’t expect the therapy will work for everyone. But, even if only some benefit, it might at least increase the possible treatment choices for women like your daughter who are reluctant to use antidepressants during pregnancy.