Post-traumatic stress disorder (PTSD) is a mental health problem that occurs when experiencing or witnessing a traumatic event, such as a traffic accident, a natural disaster, sexual abuse, the abandonment or death of a loved one… Most Of people who suffer a potentially traumatic experience do not develop this disorder, but those who suffer from it may have symptoms such as fear, anxiety, negative thoughts or memories of the traumatic event, sleep disturbances, insecurity, concentration difficulties, social isolation…
A new study by scientists at Duke University (United States) has found that adults who suffer post-traumatic stress have around 2% smaller cerebellum, an area of the brain that helps coordinate movement and balance, and which can influence emotions and memory, which are precisely affected by this disorder. The results of the work have been published in Molecular Psychiatry.
“The differences occurred largely in the posterior lobe, where many of the more cognitive functions attributed to the cerebellum seem to be located, as well as in the vermis, which is linked to many emotional processing functions,” said Ashley Huggins, lead author. of the report she helped conduct the work as a postdoctoral researcher at Duke in psychiatrist Raj Morey’s lab.
Huggins, who is now an assistant professor of psychology at the University of Arizona, hopes these results will encourage other scientists to consider the cerebellum as an important medical target in PTSD patients: “If we know which areas are involved, then we can start.” to focus interventions such as brain stimulation on the cerebellum, and potentially improve treatment outcomes,” he stated.
Focus on the cerebellum for the study and treatment of PTSD
The researchers decided to find out which comes first: whether a smaller cerebellum predisposes a person to develop PTSD, or whether it is suffering from post-traumatic stress disorder that shrinks this area of the brain. They found several brain regions implicated in PTSD, including the amygdala, which is responsible for regulating fear, and the hippocampus, a key center for processing memories and directing them throughout the brain.
The cerebellum makes up only 10% of the brain’s total volume, but contains more than half of the brain’s 86 billion nerve cells. “It’s a really complex area,” Huggins said. “If we look at how densely populated with neurons it is in relation to the rest of the brain, it is not surprising that its functions go much more than regulating balance and movement.”
Duke’s Dr. Morey, along with more than 40 other research groups that are part of a broader data-sharing initiative, combined their brain imaging scans to study PTSD as broadly and universally as possible. Finally, they obtained images from 4,215 MRI scans of adults, about a third of whom had been diagnosed with post-traumatic stress disorder.
“When we looked at the severity of PTSD, people who had more severe forms of the disorder had even less cerebellar volume.”
Even with automated software to analyze the thousands of brain scans, Huggins manually reviewed each image to ensure that the boundaries drawn around the cerebellum and its numerous subregions were accurate. The result of this exhaustive methodology was a fairly simple and consistent finding: PTSD patients had approximately 2% smaller cerebellums.
When Huggins focused on specific areas of the cerebellum that influence emotions and memory, he found similar cerebellar reductions in people with PTSD. He also discovered that the worse a person’s PTSD was, the smaller their cerebellum was. “When we looked at the severity of PTSD, people who had more severe forms of the disorder had even smaller cerebellar volume.”
The results are an important first step in looking at how and where PTSD affects the brain. Huggins hopes that this work will help others recognize the cerebellum as an important driver of complex behaviors and processes, as well as a potential target for new and current treatments for people with post-traumatic stress disorder. “If we can better understand what happens in the brain, then we can try to incorporate that information to create more effective treatments that are longer lasting and work for more people,” concludes the researcher.
