THE CONTINUUM OF PSYCHOSES BETWEEN SCHIZOPHRENIA AND BIPOLAR DISORDER - THE NEUROANATOMICAL EVIDENCE

There are several similarities in structural brain abnormalities in schizophrenia and bipolar disorder. These include lateral and third cerebral ventricular enlargement, sulcal and fissure widening, decreased cerebral volume, reduced cerebellar vermis, increased caudate volume, reduction in medial temporal and superior temporal gyrus volumes and increased frequency of subcortical white matter hyperintensities. Histologically, there are reports of histoarchitectural malformations in the superficial layer of the entorhinal cortex in bipolar disorder, suggestive of a second trimester defect in neuronal migration similar to that seen in postmortem studies of schizophrenic patients. The findings of similar neuroanatomical pathology in bipolar disorder and schizophrenia suggest that those two disorders may share a common neuropathology Since most of the morphological and histologic abnormalities in schizophrenia have been attributed to disruption in the processes of normal brain development, it is possible to conceptualize bipolar disorder and schizophrenia as parts of a continuum of neurodevelopmental lesions associated with overlapping psychopathologies.