The gold-standard treatment for post-traumatic stress disorder is exposure therapy, where patients revisit the memory of their trauma and confront settings that remind them of it. Over time, their fear and anxiety diminish as they learn to cope with memories and situations that invoke the trauma.
However, many PTSD patients don't respond to exposure therapy and require more specialized treatment.
To find a better way to help these patients, Stanford psychiatrist and neurobiologist Amit Etkin, MD, PhD, psychiatrist Ruth O'Hara, PhD, and their colleagues examined two groups of PTSD patients using behavioral and clinical assessments, along with brain-imaging and transcranial magnetic stimulation, or TMS.
In a study published in Science Translational Medicine, the team discovered that many patients who don't respond to exposure therapy have a disruption in a distinct area of the brain called the ventral attention network, or VAN.
As stated in the press release:
The VAN is critical in cognition and memory. Abnormalities in this network have been linked to a range of psychiatric conditions, including schizophrenia, depression and anxiety. The scientists found that some individuals with PTSD have both reduced VAN function and diminished ability to recall lists of words during a during a memory test. Those with both traits were not responsive to exposure therapy.
This was the first study to use biology to identify two types of people with PTSD, thereby transcending diagnosis based on clinical grounds alone, Etkin said. The researchers identified a clear brain-function marker that could be pinpointed regardless of whether the study participants were civilians or veterans, or how their clinical diagnosis was made.
By using markers like this, Etkin and O'Hara are hoping we can gain a more fundamental understanding of PTSD and better predict patients' treatment responses.
Moving forward, both scientists hope to translate these findings into more effective clinical treatments for PTSD patients.
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