Investigators used coordinate and lesion network mapping to assess whether there was a shared brain network common to multiple psychiatric disorders. In a meta-analysis of almost 200 studies encompassing more than 15,000 individuals, they found that atrophy coordinates across these six psychiatric conditions all mapped to a common brain network.
Dr. Joseph Taylor
Moreover, lesion damage to this network in patients with penetrating head trauma correlated with the number of psychiatric illnesses that the patients were diagnosed with post trauma.
The findings have “bigger-picture potential implications,” lead author Joseph Taylor, MD, PhD, medical director of transcranial magnetic stimulation at Brigham and Women’s Hospital’s Center for Brain Circuit Therapeutics, Boston, told this news organization.
“In psychiatry, we talk about symptoms and define our disorders based on symptom checklists, which are fairly reliable but don’t have neurobiological underpinnings,” said Dr. Taylor, who is also an associate psychiatrist in Brigham’s department of psychiatry.
By contrast, “in neurology, we ask: ‘Where is the lesion?’ Studying brain networks could potentially help us diagnose and treat people with psychiatric illness more effectively, just as we treat neurological disorders,” he added.
The findings were published online in Nature Human Behavior.
Beyond symptom checklists
Dr. Taylor noted that, in the field of psychiatry, “we often study disorders in isolation,” such as generalized anxiety disorder and major depressive disorder.
“But what see clinically is that half of patients meet the criteria for more than one psychiatric disorder,” he said. “It can be difficult to diagnose and treat these patients, and there are worse treatment outcomes.”
There is also a “discrepancy” between how these disorders are studied (one at a time) and how patients are treated in clinic, Dr. Taylor noted. And there is increasing evidence that psychiatric disorders may share a common neurobiology.
This “highlights the possibility of potentially developing transdiagnostic treatments based on common neurobiology, not just symptom checklists,” Dr. Taylor said.
Prior work “has attempted to map abnormalities to common brain regions rather than to a common brain network,” the investigators wrote. Moreover, “prior studies have rarely tested specificity by comparing psychiatric disorders to other brain disorders.”
In the current study, the researchers used “morphometric brain lesion datasets coupled with a wiring diagram of the human brain to derive a convergent brain network for psychiatric illness.”
They analyzed four large published datasets. Dataset 1 was sourced from an activation likelihood estimation meta-analysis (ALE) of whole-brain voxel-based studies that compared patients with psychiatric disorders such as schizophrenia, BD, depression, addiction, OCD, and anxiety to healthy controls (n = 193 studies; 15,892 individuals in total).
Dataset 2 was drawn from published neuroimaging studies involving patients with Alzheimer’s disease (AD) and other neurodegenerative conditions (n = 72 studies). They reported coordinates regarding which patients with these disorders had more atrophy compared with control persons.
Dataset 3 was sourced from the Vietnam Head Injury study, which followed veterans with and those without penetrating head injuries (n = 194 veterans with injuries). Dataset 4 was sourced from published neurosurgical ablation coordinates for depression.