Several structural differences have been shown in neuroimaging studies of people with bipolar disorder.1,2 Interestingly, it is becoming possible to separate brain abnormalities that appear to be present early in the disease – such as prefrontal cortex, striatum, and amygdala changes – from changes that appear to present later in the disease – such as those in the cerebellar vermis, and the lateral ventricles.3 It has been hypothesized therefore, that whilst these latter changes may represent the effect of illness progression, the former changes may exist before illness onset.3
References:
1. Hibar DP, Westlye LT, van Erp TG, et al. Subcortical volumetric abnormalities in bipolar disorder. Mol Psychiatry 2016; 21 (12): 1710–1716.
2. Hibar DP, Westlye LT, Doan NT, et al. Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group. Mol Psychiatry 2018; 23 (4): 932–942.
3. Strakowski SM, Delbello MP, Adler CM. The functional neuroanatomy of bipolar disorder: a review of neuroimaging findings. Mol Psychiatry 2005; 10 (1): 105–116.