Schizophrenic no more: Two subcategories in the brain redefine a blanket diagnosis

In a study of more than 300 patients, a second type of schizophrenia was discovered by observing brain matter that looks healthy, but with increased volumes of gray matter in the basal ganglia.

Penn Medicine researchers are the first to discover two distinct neuroanatomical subtypes of schizophrenia after analyzing the brain scans of more than 300 patients. The first type showed lower widespread volumes of gray matter when compared to healthy controls, while the second type had volumes largely similar to normal brains. The findings, published in the journal Brain, suggest that, in the future, accounting for these differences could inform more personalized treatment options. 

Brain scans of two brains, one with six scans representing Subtype 1 and one with four scans representing Subtype 2, number two has increased gray matter regions while number 1 has decreased gray matter regions.
Sixty percent of patients with schizophrenia (subtype 1) had decreased gray matter volumes throughout the brain compared to healthy people, which is the typical pattern seen in those with this disorder. However, researchers found that more than a third of schizophrenia patients (subtype 2) did not present with this pattern. These brains had increased volumes of gray matter in the basal ganglia, but were otherwise similar to healthy controls. (Image: Penn Medicine News)

“Numerous other studies have shown that people with schizophrenia have significantly smaller volumes of brain tissue than healthy controls. However, for at least a third of patients we looked at, this was not the case at all—their brains were almost completely normal,” says principal investigator Christos Davatzikos, the Wallace T. Miller Professor of Radiology in the Perelman School of Medicine. “In the future, we’re not going to be saying, ‘This patient has schizophrenia,’ We’re going to be saying, ‘This patient has this subtype’ or ‘this abnormal pattern,’ rather than having a wide umbrella under which everyone is categorized.”

The researchers found that 115 patients with schizophrenia, or nearly 40 percent, did not have the typical pattern of reduced gray matter volume that has been historically linked to the disorder. In fact, their brains showed increases of brain volume in the middle of the brain, in an area called the striatum, which plays a role in voluntary movement. When controlling for differences in medication, age, and other demographics, the researchers could not find any clear explanation for the variation.

“The subtype 2 patients are very interesting, because they have similar demographic and clinical measures with subtype 1, and the only differences were their brain structures,” says Ganesh Chand, a lead author and postdoctoral researcher in the radiology department.

Read more at Penn Medicine News.