Oral Abstracts

Introduction: People with bipolar disorder (BD) tend to show cortical abnormalities that appear to be associated with cognitive impairment.Impairments in tests of processing speed, attention, and executive function may represent primary impairments that have a downstream effect on wider functioning.However, the neural correlates of these impairments are not well understood; findings on brain-cognition associations are rarely replicated, likely due to limitations with traditional univariate analysis and small samples.Method: Euthymic adult BD patients (n = 56) and matched healthy controls (n = 26) underwent T1-weighted MRI scans and completed neuropsychological tests of processing speed, attention, and executive function.We utilised large public datasets to develop normative models of cortical thickness (n = 5977) to generate robust estimations of cortical abnormalities in patients.Canonical correlation analysis was used to assess multivariate brain-cognition associations.Results: BD showed impairments on tests of processing speed, attention, and executive function, compared to healthy controls.BD also showed abnormal cortical thickness in several brain regions and the pattern of abnormalities more closely resembled previous ENIGMA studies when using normative modelling, compared to the traditional case-control method.Impairments in tests of processing speed and executive function were most strongly associated with cortical thickness abnormalities in left inferior temporal, right entorhinal, and right temporal pole areas. Conclusion:Associations between cognitive impairment and cortical abnormalities can be detected in euthymic BD.Future research should continue to examine brain-cognition associations in BD by leveraging normative modelling and multivariate methods that account for relationships between cognitive impairments.Useful tools for such methods will be discussed.