Some symptoms of bipolar disorder and schizophrenia are similar, and the two conditions also share some structural changes in the brain. Reduced dendritic spine density in the dorsolateral prefrontal cortex, previously found in schizophrenia, has now been identified in bipolar disorder.
Mean spine density was significantly reduced in those with bipolar disorder compared with controls; those with schizophrenia also showed reduced spine density that just missed significance when compared with controls. There was a significant reduction in the mean number of spines per dendrite in both bipolar disorder and schizophrenia compared with controls. In addition, both individuals with bipolar disorder and schizophrenia had a reduced mean dendrite length compared with controls. Dendritic spine loss in the dorsolateral prefrontal cortex in both bipolar disorder and schizophrenia suggests that the disorders may share some common pathophysiological features, the authors say.