Neuroimaging differences between bipolar and unipolar depression

Abstract

Abstract Bipolar disorder is defined by the onset of mania; however, most of the bipolar disorder illness course is spent struggling with depression. Patients presenting with depression in the context of bipolar disorder describe similar symptoms to unipolar depression, and the two disorders are not currently distinguishable by clinical presentations. This similarity results in half of individuals with bipolar disorder being misdiagnosed for up to 10 years with unipolar depression and thus provided with inappropriate treatments. This chapter describes the neural networks believed to be related to mood disorder pathology and methods for acquiring these neural measures. It also examines neuroimaging findings from studies directly comparing bipolar disorder and unipolar depression to understand network dysfunctions that may aid in early diagnosis. Studies comparing neural measures of white matter structure, grey matter structure, neural activity, and connectivity will be reviewed. Finally, to identify neural abnormalities that are evident early in the development of the pathology, comparisons of youth with bipolar disorder versus unipolar depression and comparisons of youth at familial risk for the development of mood disorders will be reviewed.