These authors contributed equally to this work.
Overlapping and distinct gray and white matter abnormalities in schizophrenia and bipolar I disorder
Article first published online: 25 JUN 2013
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Volume 15, Issue 6, pages 680–693, September 2013
How to Cite
Overlapping and distinct gray and white matter abnormalities in schizophrenia and bipolar I disorder. Bipolar Disord 2013: 15: 680–693. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd., , , , , , .
- Issue published online: 3 SEP 2013
- Article first published online: 25 JUN 2013
- Manuscript Accepted: 13 JAN 2013
- Manuscript Received: 9 JUL 2012
- National Institute of Mental Health. Grant Numbers: MH76995, MH60004
- NSLIJ Research Institute General Clinical Research Center. Grant Number: M01 RR18535
- Advanced Center for Intervention and Services Research. Grant Number: MH74543
- Center for Intervention Development and Applied Research. Grant Number: MH80173
- bipolar disorder;
- diffusion tensor imaging;
- gray matter;
- white matter
Schizophrenia and bipolar disorder may share common neurobiological mechanisms, but few studies have directly compared gray and white matter structure in these disorders. We used diffusion-weighted magnetic resonance imaging and a region of interest based analysis to identify overlapping and distinct gray and white matter abnormalities in 35 patients with schizophrenia and 20 patients with bipolar I disorder in comparison to 56 healthy volunteers.
We examined fractional anisotropy within the white matter and mean diffusivity within the gray matter in 42 regions of interest defined on a probabilistic atlas following non-linear registration of the images to atlas space.
Patients with schizophrenia had significantly lower fractional anisotropy in temporal (superior temporal and parahippocampal) and occipital (superior and middle occipital) white matter compared to patients with bipolar disorder and healthy volunteers. By contrast, both patient groups demonstrated significantly higher mean diffusivity in frontal (inferior frontal and lateral orbitofrontal) and temporal (superior temporal and parahippocampal) gray matter compared to healthy volunteers, but did not differ from each other.
Our study implicates overlapping gray matter frontal and temporal lobe structural alterations in the neurobiology of schizophrenia and bipolar I disorder, but suggests that temporal and occipital lobe white matter deficits may be an additional risk factor for schizophrenia. Our findings may have relevance for future diagnostic classification systems and the identification of susceptibility genes for these disorders.