Molecular Architecture and Neurobiology of Bipolar Disorder

Bipolar disorder (BP), first conceptualized as a distinct disorder in the 1850s by French psychiatrist Jean-Pierre Falret, is defined by episodic and extreme fluctuations in mood, encompassing both mania and depression. Uncertainties about the validity of categorical phenotypic constructs in psychiatry have fueled efforts to explain psychopathology from a dimensional perspective. In this chapter we review the state of progress in genetic investigations of BP and other syndromes, as well as efforts to assay quantitative measures hypothesized to represent key dimensions of psychopathology. We provide an overview of current knowledge regarding the biological underpinnings of BP, framing our discussion in relation to its key clinical features. As genetic studies of BP extend their scope to include much larger samples and to incorporate more sophisticated phenotyping strategies, we can expect to obtain a substantially greater understanding of the genetic architecture of the syndrome.