Clinical and neurostructural characteristics among youth with familial and non-familial bipolar disorder: Family history and youth bipolar disorder.

Background: Bipolar disorder (BD) is highly heritable and often severe, particularly when illness onset occurs early in life. There is limited knowledge regarding the clinical and neurostructural correlates of family history of BD among youth with BD.

Methods: Clinical characteristics were evaluated in 197 youth with BD, ages 13-20 years, including 87 with familial BD and 110 with non-familial BD. Structural neuroimaging was examined in a subsample of familial BD (n=39), non-familial BD (n=42), and healthy control (HC, n=58) youth. Region of interest (ROI) analyses of anterior cingulate cortex (ACC), inferior frontal gyrus (IFG), and amygdala were complemented by whole-brain vertex-wise analyses.

Results: Youth with familial BD had more family history of other psychiatric disorders, less severe worst manic episode, and less treatment with lithium, selective serotonin reuptake inhibitor (SSRI) antidepressants, and any lifetime psychiatric medications. None of these findings survived after correction for multiple comparisons. There were no significant between-group differences in ROI analyses. In whole-brain analyses, significant differences in cortical thickness were as follows: familial and non-familial BD < HC in left precentral gyrus and right inferior parietal lobe; familial BD < HC in left superior frontal gyrus; non-familial BD < HC in right precentral gyrus.

Limitations: Relatives did not complete full diagnostic interviews.

Conclusions: There were relatively few differences in clinical and neurostructural correlates related to family history of BD in youth with BD. Current findings suggest that family history of BD is not a strong contributor to the clinical or neuroimaging phenotypes in youth with BD.