"Promising results": a new avenue for treating depression using ultrasound

An encouraging study. French researchers are attempting to treat depression using ultrasound and are showing "promising results," reports a press release from the French National Institute of Health and Medical Research (Inserm) on Monday, May 5.

Depression is a mental illness that affects "one in five people during their lifetime." "Major depressive episodes are the most common mental disorders in the world," Inserm emphasizes, and the risk of suicide is "responsible for several thousand deaths per year in France."

According to a Public Health France Barometer , 12.5% ​​of adults aged 18 to 85 surveyed in 2021 said they had experienced a major episode of depression. This number has been increasing since 2017.

While drug treatments for depression have advanced, they are still not enough to treat the illness. One-third of patients do not respond adequately to antidepressants, which also have a delay in action of several weeks.

Seeking a faster therapeutic approach, scientists have previously attempted brain stimulation of regions involved in depression. But until now, this stimulation required the implantation of intracerebral electrodes. "This is an invasive procedure associated with significant neurosurgical risk, limiting its accessibility to a small number of patients," notes Inserm.

In the study conducted by researchers and doctors from GHU Paris, Inserm, CNRS, Université Paris Cité and ESPCI Paris-PSL and published on April 29 in the medical journal Brain Stimulation , a new method is presented after 25 years of research. This involves the use of "acoustic lenses concentrating ultrasound with unprecedented precision."

These lenses, "uniquely manufactured and customized for each patient," allow ultrasound "to compensate for distortions in ultrasound waves caused by passing through the skull," explains Inserm. Without these lenses, the irregularity in the thickness of the skull can deflect ultrasound waves and limit their ability to reach the target area.

"The precision transcranial ultrasound stimulation thus obtained represents a leading technological advance in the field of personalized medicine and neuroscience," the Institute said.

Before adding: "for the first time it allows for targeted, precise and non-invasive stimulation of deep brain structures (...) with a transportable device."

For five days, this ultrasound treatment was tested on five people suffering from severe, drug-resistant depression. By the fifth day of the protocol, the severity of their depression had been reduced by an average of more than 60%. Inserm also noted "the absence of serious adverse events" and the absence of pain or discomfort experienced by patients during the sessions.

However, this study is not enough. "Although the results are encouraging, they must be interpreted with caution, as this is a first safety study on a limited number of patients and without a placebo group," the researchers state. Further studies on larger cohorts are planned.