New Israeli study shows promise of deep-brain stimulation for schizophrenia

Researchers at Rambam Health Care Campus in the northern city of Haifa have developed a deep-brain stimulation method aimed at countering schizophrenia. The innovative study could potentially lead to a breakthrough for some 21 million people worldwide who suffer from the serious, lifelong mental illness.

According to the Israeli mental health organization Ozma, an estimated 70,000 people in Israel live with schizophrenia – roughly one in 143 individuals. Symptoms of the disorder include hallucinations and delusions, and it can also impair thinking and speech.

“The study proposes a new therapeutic direction, which may in the future expand the treatment options for patients with schizophrenia who do not respond sufficiently to existing treatments,” explained Dr. Nir Asch, a doctor and researcher in the psychiatric department.

Israeli researchers are cautiously optimistic that the new therapy could potentially restore functions that control learning, decision-making, and movement in individuals suffering from schizophrenia. The groundbreaking study was led by the prominent neuroscientist and Israel Prize laureate, Professor Hagai Bergman, of the Hebrew University in Jerusalem. 

“A problem we have with many psychiatric diseases is that we define them by the symptoms,” Asch told The Times of Israel. “In our paper, we provide a clear theory about what is happening on a mechanical level in the brain, and also a way to solve it."

Asch emphasized the importance of addressing the global challenge of schizophrenia. 

“The World Health Organization (WHO) says that 21 million people around the world have schizophrenia,” he said. “One-third of these are what we call treatment resistant. This is a big burden. So, I think that we should care,” he argued. The average life expectancy among people with schizophrenia is nine years shorter than that of the general population, according to the WHO. 

The key to understanding schizophrenia is understanding how the brain works, according to Asch.

“Basically, the brain is a prediction machine,” he assessed. “It tries to predict what will happen. It builds a model. It asks, ‘What is the situation? What is happening around me?’ Then it receives the evidence from the world through the senses.”

However, these fundamental brain functions are disrupted among individuals with schizophrenia, which he argues makes it “extremely difficult to change their internal model even when the world around them changes.” 

“They are kind of stuck in their own model,” Asch explained. “The input is there, but they don’t relate.”

“This cognitive inflexibility is one of the hallmarks of the disease,” he emphasized. “It’s very hard for them to understand that something has changed in the world. They’re stuck with hallucinations and delusions, without any input from the world.”

The study, led by Asch and aimed at addressing this challenge, examined the impact of DBS on two female African green monkeys. 

“Their cognitive flexibility was reduced significantly, and their random exploration, their chaotic behavior, increased significantly,” he said. The research team eventually developed a method to stimulate a region of the brain associated with decision-making. 

“The cognitive inflexibility was cured,” Asch explained. “The monkeys returned to the levels of when they were healthy, and they were also much less chaotic."

Looking ahead with optimism, Asch revealed that the research will eventually move to clinical trials in humans. 

“Because the study was successfully performed on non-human primates, whose brains are remarkably similar to those of humans, we’re already meeting to discuss the best way to move forward,” he said.

“It can be very frustrating as a doctor when we don’t have great treatments,” Asch acknowledged. “If we can add more tools that are effective and pave the way to recovery, then it would be so wonderful."