A major component of understanding the pathogenesis of mood and anxiety disorders is expected to involve elucidation of abnormalities of brain structure and function associated with these conditions. Historically, post-mortem histopathological and neurochemical assessments constituted the primary methods for investigating abnormalities of brain structure and function in psychiatric disorders. However, the significance of the results from such studies has been limited by the relatively poor availability of specimens from subjects with mood and anxiety disorders who had been unmedicated and clinically well-characterized antemortem. By allowing for in vivo human studies, medical imaging technologies afford efficient, accurate, and non-invasive alternatives for characterizing brain structure and function. The recent, rapid development of magnetic resonance imaging (MRI) technology, in particular, has provided powerful tools for assessing a wide range of cerebral physiological and morphological characteristics. To optimally exploit the potential of rapidly evolving MRI capabilities and hardware in investigations of mood and anxiety disorders, new techniques and applications must be tested and developed. The technical development protocol proposed herein will assess new imaging techniques and hardware, and will develop novel cognitive tasks for application in the study of mood and anxiety disorders.