“There was a constant chattering in my brain: It was my own voice talking about depression, agony, hopelessness,” she said. “I told my husband, ‘I’m going down and I’m heading toward suicide.’ There seemed to be no other option.”

Lehman’s psychiatrist had heard of the SAINT study and referred her to Stanford. After researchers pinpointed the spot in her brain that would benefit from stimulation, Lehman underwent the therapy.

“By the third round, the chatter started to ease,” she said. “By lunch, I could look my husband in the eye. With each session, the chatter got less and less until it was completely quiet.

“That was the most peace there’s been in my brain since I was 16 and started down the path to bipolar disorder.”

In transcranial magnetic stimulation, electric currents from a magnetic coil placed on the scalp excite a region of the brain implicated in depression. The treatment, as approved by the FDA, requires six weeks of once-daily sessions. Only about half of patients who undergo this treatment improve, and only about a third experience remission from depression.

Stanford researchers hypothesized that some modifications to transcranial magnetic stimulation could improve its effectiveness. Studies had suggested that a stronger dose, of 1,800 pulses per session instead of 600, would be more effective. The researchers were cautiously optimistic of the safety of the treatment, as that dose of stimulation had been used without harm in other forms of brain stimulation for neurological disorders, such as Parkinson’s disease.

Other studies suggested that accelerating the treatment would help relieve patients’ depression more rapidly. With SAINT, study participants underwent 10 sessions per day of 10-minute treatments, with 50-minute breaks in between. After a day of therapy, Lehman’s mood score indicated she was no longer depressed; it took up to five days for other participants. On average, three days of the therapy were enough for participants to have relief from depression.

“The less treatment-resistant participants are, the longer the treatment lasts,” said postdoctoral scholar Eleanor Cole, PhD, a lead author of the study.

Strengthening a weak connection

The researchers also conjectured that targeting the stimulation more precisely would improve the treatment’s effectiveness. In transcranial magnetic stimulation, the treatment is aimed at the location where most people’s dorsolateral prefrontal cortex lies. This region regulates executive functions, such as selecting appropriate memories and inhibiting inappropriate responses.

For SAINT, the researchers used magnetic-resonance imaging of brain activity to locate not only the dorsolateral prefrontal cortex, but a particular subregion within it. They pinpointed the subregion in each participant that has a relationship with the subgenual cingulate, a part of brain that is overactive in people experiencing depression.

In people who are depressed, the connection between the two regions is weak, and the subgenual cingulate becomes overactive, said Keith Sudheimer, PhD, clinical assistant professor of psychiatry and a senior author of the study. Stimulating the subregion of the dorsolateral prefrontal cortex reduces activity in the subgenual cingulate, he said.

To test safety, the researchers evaluated the participants’ cognitive function before and after treatment. They found no negative side effects; in fact, they discovered that the participants’ ability to switch between mental tasks and to solve problems had improved — a typical outcome for people who are no longer depressed.

One month after the therapy, 60% of participants were still in remission from depression. Follow-up studies are underway to determine the duration of the antidepressant effects.

The researchers plan to study the effectiveness of SAINT on other conditions, such as obsessive-compulsive disorder, addiction and autism spectrum disorders.

‘Resilient and stable’

The depression Lehman woke up to almost two years ago was the worst episode she had ever experienced. Today, she said, she is happy and calm.

Since undergoing SAINT treatment, she has completed a bachelor’s degree at the University of California-Santa Barbara; she had dropped out as a young woman when her bipolar symptoms overwhelmed her studies.

“I used to cry over the slightest thing,” she said. “But when bad things happen now, I’m just resilient and stable. I’m in a much more peaceful state of mind, able to enjoy the positive things in life with the energy to get things done.”

Graduate student Katy Stimpson and Brandon Bentzley, MD, PhD, a medical fellow in psychiatry and behavioral sciences, are also lead authors.

Other Stanford co-authors are former lab manager Merve Gulser; graduate students Kirsten Cherian, Elizabeth Choi, Haley Aaron and Austin Guerra; Flint Espil, PhD, clinical assistant professor of psychiatry and behavioral sciences; research coordinators Claudia Tischler, Romina Nejad and Heather Pankow; medical student Jaspreet Pannu; postdoctoral scholars Xiaoqian Xiao, PhD, James Bishop, PhD, John Coetzee, PhD, and Angela Phillips, PhD; Hugh Solvason, MD, PhD, clinical professor of psychiatry and behavioral sciences; research manager Jessica Hawkins; Booil Jo, PhD, associate professor of psychiatry and behavioral sciences; Kristin Raj, MD, clinical assistant professor of psychiatry and behavioral sciences; Charles DeBattista, MD, professor of psychiatry and behavioral sciences; Jennifer Keller, PhD, clinical associate professor of psychiatry and behavioral sciences; and Alan Schatzberg, MD, professor of psychiatry and behavioral sciences.

The research was supported by Charles R. Schwab, the Marshall and Dee Ann Payne Fund, the Lehman Family Neuromodulation Research Fund, the Still Charitable Fund, the Avy L. and Robert L. Miller Foundation, a Stanford Psychiatry Chairman’s Small Grant, the Stanford CNI Innovation Award, the National Institutes of Health (grants T32035165 and UL1TR001085), the Stanford Medical Scholars Research Scholarship, the NARSAD Young Investigator Award and the Gordie Brookstone Fund.

A 1:2:1 podcast on the study's findings features Williams in conversation with Paul Costello, senior communications strategist and adviser for Stanford Health Care and the School of Medicine.