Schizophrenia and Bipolar Disorder: Differences and Overlaps

Wolfgang Maier; Astrid Zobel; Michael Wagner


Curr Opin Psychiatry. 2006;19(2):165-170. 

In This Article


Evidence suggesting that schizophrenia has etiological factors and pathophysiological pathways in common with bipolar disorder is now increasing; overlapping clinical features might be a consequence. Well documented examples are susceptibility genes for neuregulin-1 and G72/G30, which are involved in neurodevelopment, glutamatergic transmission, or both; disturbed connectivity that is apparent from white matter abnormalities resulting in the observed cognitive, emotional symptoms, or both already in the prodromal phase. On a clinical level depression is a precursor in the majority of cases in both disorders. Beyond these commonalities, disease-specific features (as different risk factors and neuropathological features) are also apparent. It can be concluded that the relationship between both disorders does not fit into a 'nosological' dichotomy as originally conceived. Currently, several lines of evidence suggest that patients with psychotic features in bipolar disorder are very similar to patients with schizophrenia in genetic and neurobiological respects. Remodeling of the complex relationship between both disorders will become possible once the relationship between an exhaustive set of specific susceptibility genes with structure and function of brain systems as well as with each of the two disorders and their symptoms is elucidated.


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