ABSTRACT
Bipolar disorder (also known as manic-depressive illness) is a severe and often lifethreatening illness (1) that has recently been recognized, by the Institute of Medicine, as a chronic condition that requires priority action (2). The costs associated with disability and premature death from major mood disorders represent an economic burden of tens of billions of dollars annually in the United States alone (3). Despite the devastating impact that bipolar disorder has on the lives of millions worldwide, there is still little known concerning its underlying etiology and neurobiology. This lack of knowledge regarding the cellular underpinnings of bipolar disorder has undoubtedly contributed to the lack of development of new treatments. Therefore, studies of the classic neurotransmitter systems, as well as studies of genetics, neuroendocrine systems, neuropeptides, circadian rhythms, intracellular signaling pathways, mitochondrial function, fatty acids, neurotrophic factors, and immune function (and the interplay of these systems), are critically needed to fully understand the pathophysiology of bipolar disorder. This chapter reviews the current relevant studies on the pathophysiology of bipolar disorder, and attempts to build a framework for the direction of future research.
