A new study suggests that the neural networks (connections between brain areas) in people with a particular subtype of schizophrenia differ significantly compared to people with other subtypes of the disorder. These differences were found by using magnetic resonance imaging (MRI).

The study was published March 18th in JAMA Psychiatry, by a team led by 2014 NARSAD Independent Investigator Aristotle Voineskos, M.D., Ph.D., Anne Wheeler, Ph.D., 2013 NARSAD Young Investigator, is the study’s first author. Both Drs. Voineskos and Wheeler are from the Campbell Family Mental Health Institute at the Centre for Addiction and Mental Health in Toronto, Ontario.*  

 

The researchers found that people diagnosed with “deficit schizophrenia”––marked by diminished emotional expression, lack of speech, and lower social drive––had a different pattern of brain activation and connection compared to people with other subtypes of schizophrenia, bipolar I disorder, and healthy people.

Previous evidence had suggested that specific circuits in the brain’s frontoparietal area and temporal lobes were altered in deficit schizophrenia. However, other studies had produced conflicting results. The researchers wanted to see what they might find by using MRI to image the brain, analyzing the results with a “connectomic” approach––that is, focusing on the strength of the connections between specific brain areas.

The imaging results showed that people with deficit schizophrenia had altered connections in several brain regions. Specifically, neural circuits that connect the inferior frontal, inferior parietal, and middle and superior temporal regions had increased density in these patients. The results suggest that the neural circuitry in these areas is impaired, which may lead to the negative symptoms. For example, the frontoparietal area, where differences were found, is involved in the mirror neuron system, which is activated during emotion-based sharing and understanding.

This deeper understanding of how specific neural circuits are altered in deficit schizophrenia point the way to future studies looking more deeply at this altered connectivity. The study results can also help guide the development of treatment for schizophrenia symptoms.

*The research team also included: Anil Malhotra, M.D., two-time NARSAD grantee and a member of the Foundation’s Scientific Council; Philip R. Szeszko, Ph.D. (1998, 2003 Young Investigator [YI] and 2009 Independent Investigator [II]; George Foussias, M.D, M.Sc. (2010 YI); and Gary J. Remington, M.D., Ph.D., FRCPC (2002 II).

Read the abstract.