ABSTRACT
The first report of an electroencephalographic (EEG) recording from amammal was made more than a century ago (1) and the first human recording over 65 years ago (2). A search of PubMed for papers referring to EEG or event-related potentials (ERPs) and bipolar disorder (BD) flags nearly three hundred items (between 1966 and December 2005). However, of these papers, over two-thirds are more than 10 years old. EEG and ERP studies are not new but certainly are not increasing at the rate seen with other experimental methodologies in psychiatric illnesses, such as functional magnetic resonance imaging (fMRI) and molecular studies. Put bluntly, EEG is not a “sexy” topic. This stems largely from the technique not delivering important findings after years of study, with a few notable exceptions such as the diagnosis of epilepsy and sleep disorders. However, EEG and ERP techniques still have much to offer in the further elucidation of the pathophysiology of mood disorders if used in appropriate ways. In the past, much reliance has been placed on the visual inspection of paper and ink EEG recordings and rather simple ERP paradigms with no a priori hypothetical rationale behind their design. While this situation continues in clinical electrophysiology to a large extent, the increasing use of novel computational analysis of EEG and ERP data, often coupled with specific pharmacological or cognitive challenges, offers exciting prospects for the future. This chapter is a selective review of EEG and ERP data to illustrate this argument. It is not a comprehensive review of all of the EEG studies in BD. In particular, sleep EEG research is not covered at all. The chapter is written with the non-EEG specialist bipolar researcher in mind.
