A pattern of loss of gray matter in certain areas of our brains is involved in a number of mental-health problems ranging from depression to OCD to schizophrenia, researchers have discovered.
Neuroscientists at Stanford University say six major psychiatric disorders are linked to loss of brain matter in three distinct brain regions, all involved in higher cognitive functions including self-control and in certain types of memory.
The researchers analyzed hundreds of brain imaging studies covering depression, addiction, bipolar disorder, anxiety, schizophrenia and obsessive-compulsive disorder.
They were asking themselves the question, is there a common biological basis for mental illness?
"During the past several decades, psychiatry has focused on establishing diagnostic categories based on clinical symptoms," the researchers write in the journal JAMA Psychiatry.
Most previous studies involving neuroimaging have examined deviations in brain structure in patients with a single, specific diagnosis rather than trying see if there's a common brain link between more than one form of mental illness, they said.
"We wanted to test a very simple question that simply hadn't been asked," namely whether often-seen psychiatric disorders have a common structure in the brain, says study senior author Dr. Amit Etkin.
Analyzing data from 193 studies containing brain scans of 7,381 patients with a range of psychiatric disorders, they found a common loss of gray matter in three areas deep inside the brain: the dorsal anterior cingulate cortex, and the left and right insula.
These areas, networked together, are linked to what is known as executive functioning, responsible for the management of cognitive processes such as reasoning, self-control and decision-making, the researchers explain.
"They work together, signaling to other brain regions when reality deviates from expectations -- that something important and unpredicted has happened, or something important has failed to happen," Etkin says.
A failure of this "alarm bell" function may be behind psychiatric disorders in which patients lose the ability to distinguish reality from an internal fantasy, researchers say.
"As a clinician, I see commonalities between patients [with different diagnoses], but until I did this study, I was unable to understand what they were and how they operate," he says of the study's findings.
The discovery of shared neural structural changes across a surprising number of psychiatric disorders could allow therapies found to be effective treating one type of disorder to be used to treat others conditions, he says.
There are plans for future studies to see if brain activity as well as brain structure exhibits similarities that span different mental disorders, he adds.
