Fig 2 - uploaded by Renata Rozovsky
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3D visualization of the white matter tracts showing group differences across four groups (BD, healthy OBP and OCP, non-BD OBP and OCP, and OHP). Bar plots represent the mean FA with the main effect of group (FDR-corrected) in 4 clusters. Red brackets show significant differences in BD versus other groups (q < 0.05). Green brackets show significant differences in OHP versus other groups (q < 0.05). Blue brackets show significant differences between healthy OBP and OCP and non-BD OBP and OCP. Error bars represent standard deviations. BD -offspring with BD; OBP-offspring of bipolar parents; OCP-offspring of comparison parents; OHP-healthy offspring of healthy parents. A Left Anterior Thalamic Radiation. B Right Anterior Thalamic Radiation. C Anterior cluster of the Right Cingulum Bundle. D Middle cluster of the Right Cingulum Bundle.
Source publication
Bipolar disorder (BD) is highly heritable. Identifying objective biomarkers reflecting pathophysiological processes predisposing to, versus protecting against BD, can help identify BD risk in offspring of BD parents. We recruited 21 BD participants with a first-degree relative with BD, 25 offspring of BD parents, 27 offspring of comparison parents...
Context in source publication
Context 1
... In bilateral ATR clusters and the middle cluster of the right CB, healthy, but not non-BD, OBP and OCP showed higher FA than OHP. In bilateral ATR clusters and the anterior cluster of the right CB, non-BD OBP and OCP showed higher FA than BD. FA was higher in healthy OBP and OCP versus non-BD OBP and OCP in the right ATR cluster(all qs < 0.05; Fig. 2; Supplementary Table ...
Citations
Background
Identifying neural predictors of worsening subthreshold hypomania severity can help identify risk of progression to BD. While diffusion Magnetic Resonance Imaging (dMRI) studies reported white matter microstructural abnormalities in tracts supporting emotional regulation in individuals with BD, it remains unknown whether similar patterns of white matter microstructure predict worsening of subthreshold hypomania severity in non-BD individuals.
Methods
dMRI data were collected in: 81 non-BD individuals recruited across a range of subthreshold depression and hypomania, and followed for six months; and independent samples of 75 BD and 58 healthy individuals. All individuals were assessed using standardized diagnostic assessments, mood and anxiety symptom rating scales. Global probabilistic tractography and a tract-profile approach examined fractional anisotropy (FA), a measure of fiber collinearity, in tracts supporting emotional regulation shown to have abnormalities in BD: forceps minor (FMIN), anterior thalamic radiation (ATR), cingulum bundle (CB), and uncinate fasciculus (UF).
Results
Lower FA in left CB (middle, β = −0.22, P = 0.022; posterior, β = −0.32, P < 0.001), right CB (anterior, β = −0.30, P = 0.003; posterior, β = −0.27, P = 0.005), and right UF (frontal, β = −0.29, P = 0.002; temporal, β = −0.40, P < 0.001) predicted worsening of subthreshold hypomania severity in non-BD individuals. BD versus healthy individuals showed lower FA in several of these segments: middle left CB (F = 8.7, P = 0.004), anterior right CB (F = 9.8, P = 0.002), and frontal right UF (F = 7.0, P = 0.009). Non-BD individuals with worsening 6-month hypomania had lower FA in these three segments versus HC and non-BD individuals without worsening hypomania, but similar FA to BD individuals.
Limitations
Relatively short follow-up.
Conclusions
White matter predictors of worsening subthreshold hypomania in non-BD individuals parallel abnormalities in BD individuals, and can guide early risk identification and interventions.
