White matter (WM) volume decreases in areas of the frontal, occipital, and parietal lobes are present in bipolar offspring prior to the development of any psychiatric symptoms, and may be a correlate of familial risk to bipolar disorder, according to a recent study. Researchers obtained magnetic resonance images from 115 child and adolescent offspring of bipolar disorder type I subjects and 57 healthy child and adolescent offspring of healthy parents. Offspring of parents with bipolar disorder were divided into healthy bipolar offspring (n=47) or symptomatic bipolar offspring (n=68), according to presence or absence of childhood-onset psychopathology. They found:

• There were no differences in gray matter (GM) volumes across groups.
• Healthy bipolar offspring presented with decreased WM volumes in areas of the right frontal, temporal, and parietal lobes, and in the left temporal and parietal lobes compared to healthy control offspring.
• Symptomatic bipolar offspring did not present with any differences in WM volumes compared to either healthy bipolar offspring or healthy control offspring.