Identification of addiction-associated variants in genes that are likely to alter the quality of brain connections provides a first step toward defining a new neurobiology for the underpinnings of specific diseases and phenotypes. For many of these diseases and phenotypes, only little current research focuses on direct study of brain connections. The “connectivity constellation” concepts that we introduce here support studies that develop and use current and novel means for assessing the qualities and quantities of brain connections, especially in contexts in which they assess their functional properties. We have identified contributions of connectivity constellation genes to volumes of the same brain regions in which many of these genes are expressed. This convergence may provide new insights into data that documents individual differences in frontal lobe volume and/or in function, detected by volumetric, deoxyglucose PET and/or fMRI imaging, for virtually all of the “connectivity constellation” phenotypes or disorders noted here [8, 117].
