The economic and personal burden of depression is overwhelming, contributing to pervasive and chronic disability in occupational and interpersonal functioning (e.g., Greenberg et al., 2003; Judd et al., 2000), and substantially increased risk for suicide (Kessler, DuPont, Berglund, & Wittchen, 1999). In the quest to reduce this burden, endophenotypes (Gottesman & Gould, 2003; Iacono, 1998), measurable endogenous characteristics of an individual that are related to underlying mechanisms conferring risk, may prove useful in identifying a subset of the population at risk for developing depression, and may ultimately assist in identifying functional mechanisms that may point to new treatments and preventions. A potential promising endophenotype is resting frontal electroencephalographic (EEG) asymmetry.
