Canadian researchers may hold the key to safely and effectively treating moderate to severe depression in pregnant women without posing a risk to their developing babies.

In a world first, researchers at Women's College and Mount Sinai hospitals, and Centre for Addiction and Mental Health in Toronto are studying the use of a gentle form of brain stimulation called transcranial direct current stimulation (tDCS) to treat depression in women who are concerned that traditional drug therapies may pose a risk to the fetus.

Multiple studies have found tDCS to be effective at treating moderate to severe depression in the general population after just two to three weeks of treatment.

The researchers hope that their small study can prove the treatment to be safe and effective in pregnant women, paving the way for a larger, multi-site, randomized clinical trial and, ultimately, approval for use in patients.

Estimates suggest that one in 10 pregnant women suffer from depression. .

Traditional drug therapies like SSRI’s and older medications for depression are considered generally safe during pregnancy. But some have been linked to heart malformations and pulmonary hypertension in the newborns. Their long-term effects also remain unclear.

However, untreated depression can also be harmful to the fetus. Maternal depression is linked to premature birth, smaller babies and is the number one risk factor for post-partum depression.

“If a fetus is exposed to a woman who is very depressed during pregnancy, there is a strong likelihood that that child will have a pattern of depression and the problems of mental illness. So it’s a way of preventing mental illness before it happens,” researcher Dr. Daniel Blumberger told CTV News.

Meanwhile, psychotherapy is an effective treatment for mild depression, but usually ineffective on its own for women with moderate to severe depression. If it does work, it can take weeks or months to prove helpful, while leaving the developing fetus exposed to the negative effects of untreated maternal depression.

Researcher Dr. Simone Vigod said there are many ways to treat depression; it’s a matter of finding ways that are acceptable to pregnant women, so they won’t go without help.

“We need to find acceptable ways to treat it so people will take the treatments,” she said.

'It changed my world'

To treat a patient using tDCS, doctors place two electrodes on the scalp to directly stimulate the part of the brain that functions abnormally during depression: the dorsolateral prefrontal cortex.

Patients receive the treatment for 20 to 30 minutes every day over a three-week period. For the current study, researchers also monitor the fetus's vital signs.

Previous research has found that tDCS stimulates the brain, but does not affect the patient's heart rate, blood pressure or body temperature.

Therefore, researchers believe it poses no apparent risk to the fetus.

Tatania Samburova, a Russia-born economist who immigrated to Canada two years ago, developed depression before becoming pregnant. Her depression left her feeling hollow, even suicidal.

“You do not feel yourself living. You do not want anything, you do not want to go somewhere, to do something,” she said.

Her doctor offered her antidepressants, but, while she knew they would offer her relief, she decided against using them over fears they may harm her child.

“Even if it will bring me, right now, some kind of relief, it can also affect the life of a little child,” she said.

Instead, she travelled to Mount Sinai every day for three weeks to be treated as part of the study. She doesn’t know for sure if she received a sham treatment or the actual tDCT stimulation but suspects she had the actual therapy because within days her appetite returned and she felt her mood lifting.

“This treatment brought happiness back to me; it brought life back to me,” she said.

She remains well today, with her baby due mid-March.

Vigod notes that some women are so desperate for treatment that they are not waiting for the study results.

“I can tell you anecdotally that women are buying devices like this in the U.S. and using them at home, but they haven’t really been tested to see if it works to make the depression better.”

Researchers expect to have their results this fall, and several other Canadian hospitals are prepared to serve as host sites if the study is expanded.

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip