Decreased volumes of subgenual cingulate(SGC) have been reported primarily among familial bipolarpatients, which is one of the hallmarks of an endophenotype. In order to investigate specificity of SGC volume abnormalitiesto familial mood disorders and to test whether SGCvolumes represent an endophenotype for BD, we measured SGC volumes in young affected and unaffected relatives of bipolar patients (high-risk design) and in sporadic bipolar patients.