Structural Brain Abnormalities Linked to Schizophrenia

A collaborative international study has discovered that individuals diagnosed with schizophrenia often have smaller brain regions than people without mental illness.

The finding provides a clue into how the condition may develop and respond to treatment.

In the study, scientists at more than a dozen locations across the United States and Europe analyzed brain MRI scans from 2,028 schizophrenia patients and 2,540 healthy controls.

The findings, which experts believe will help to advance improved understanding of the mental disorder, appear in the journal Molecular Psychiatry.

The work was the product of the Enhancing Neuroimaging Genetics through Meta-Analysis project (ENIGMA), from the Schizophrenia Working Group. The Group is co-chaired by Dr. Jessica Turner, associate professor of psychology and neuroscience at Georgia State University, and Dr. Theo van Erp, assistant research professor in psychiatry at the University of California, Irvine.

“This is the largest structural brain meta-analysis to date in schizophrenia, and specifically, it is not a meta-analysis pulled only from the literature,” said Turner.

“Investigators dug into their desk drawers, including unpublished data to participate in these analyses. Everyone performed the same analyses using the same statistical models, and we combined the results. We then identified brain regions that differentiated patients from controls and ranked them according to their effect sizes.”

The team found individuals with schizophrenia have smaller volume in the hippocampus, amygdala, thalamus, nucleus accumbens, and intracranial space than controls, and larger pallidum and ventricle volumes.

The study demonstrates that collaborative data analyses can be used across brain phenotypes and disorders. This approach encourages analysis and data-sharing efforts to further understanding of severe mental illness.

The ENIGMA collaborations include working groups for other disorders such as bipolar disorder, attention deficit, major depression, autism and addictions, who are all doing these same analyses.

Researchers say the next step is to compare the effects across disorders, to identify which brain region is the most affected in which disorder, and to determine the effects of age, medication, environment, and symptom profiles across these disorders.

“There’s the increased possibility, not just because of the massive data sets, but also because of the collaborative brain power being applied here from around the world, that we will find something real and reliable that will change how we think about these disorders and what we can do about them,” Turner said.

Source: Georgia State University/EurekAlert