Researchers note that advances in magnetic resonance imaging (MRI) acquisition and analyses over the last two decades have enabled the identification of neuroanatomical abnormalities in a range of mental disorders.
Bipolar disorder causes substantial suffering and disability, but most patients can be successfully treated with mood stabilizing medication, such as lithium or valproate, and with antipsychotic or antidepressant medication during episodes of illness exacerbation.
MRI studies comparing patients with bipolar disorder and healthy volunteers have demonstrated subtle grey matter volume deficits in patients, especially in brain regions underpinning mood regulation. Prior studies also suggest bipolar is associated with white matter disorganization in tracts interconnecting distributed brain regions.
However, researchers note that many studies present considerable diversity in their findings.
Therefore, investigators reviewed studies that included in vivo neuroanatomical imaging of the brain during bipolar interventions. They observed that different uses of psychopharmacological treatment was associated with alterations in neuroanatomy and thus an important source of this heterogeneity.
Investigators discovered that among the larger sample size and more powerful studies, or in those that accounted for individual variation, bipolar medications appear to help restore brain anatomy to a more normative state.
This includes evidence that use of mood stabilizers such as lithium is associated with increased grey matter volume especially in brain regions underpinning mood regulation, as well as normalization of white matter disconnectivity.
This generally restorative effect of mood stabilizers on brain anatomy mirrors similar findings for brain physiology identified by functional neuroimaging studies.