A man suffering from severe depression for over 30 years has reportedly achieved remission thanks to a custom brain “pacemaker” that activates specific areas of his brain. “He felt joy for the first time in years,” says Damien Fair from the University of Minnesota.
People often develop a resistance to depression treatments, typically defined as causing little improvement after trying at least two types of antidepressants. While treatments like electroconvulsive therapy (ECT) may help, they are often ineffective. “Such treatments offer a one-size-fits-all approach, targeting the same brain area for everyone,” Fair explains, noting individual brain differences might mean the right areas aren’t being stimulated.
Fair’s team adopted a personalized method for a 44-year-old man initially hospitalized for depression at 13. Despite trying 20 treatments, including antidepressants, talk therapies, and ECT, he found no lasting relief. “His case was one of the most severe I’ve seen; he attempted suicide three times,” Fair notes.
The researchers conducted a 40-minute brain scan using MRI to outline four networks linked to depression in the man’s brain. Notably, his salience network, crucial for processing stimuli, was four times larger than average. Fair suggests this might have worsened his symptoms.
The team then surgically inserted four clusters of electrodes through two small holes in his skull. Three days later, using external wires, they sent weak electrical pulses to stimulate each of the four brain networks separately. Stimulating the default mode network, which relates to introspection and rumination, brought the man to tears of joy. “I was just elated,” Fair comments.
Stimulating both the action-mode and salience networks evoked a sense of calmness, while targeting the frontoparietal network, involved in decision-making, improved his focus.
Based on his feedback, the researchers linked the electrode wires to two small batteries implanted near his collarbone, allowing him to benefit from this “brain pacemaker” outside the hospital. This device stimulated the brain’s networks for one minute every five minutes during the day.
Over the subsequent six months, the man used an app connected wirelessly to the pacemaker to alternate between different brain stimulation patterns every few days, recording his depression symptoms daily. The team analyzed and optimized the stimulation monthly for six months post-surgery.
Remarkably, by seven weeks post-surgery, he no longer reported suicidal thoughts, and after nine months, he achieved remission based on the Hamilton depression rating scale. This improvement persisted for over two and a half years, aside from a slight decline after contracting COVID-19.
“This result is incredible,” says Mario Juruena from King’s College London. “It’s an important proof-of-concept for treating resistant, hard-to-treat depression patients.”
Compared to previous personalized brain stimulation efforts using electrode implants, this treatment entailed fewer computational resources and a shorter hospital stay.
The man’s enlarged salience network may have influenced his positive response. While this enlargement could be a common aspect of depression, Juruena suggests it’s too soon to conclude that others with depression, lacking such an enlargement, would experience similar outcomes.
Juruena emphasizes the need for a randomized controlled trial, randomly assigning many depression patients to receive either the stimulation or a placebo, to verify the approach’s safety and efficacy. Fair hopes to conduct such trials after further individual case testing within two years.
