an analytic tool involving the calculation of network properties that can be used to examine the organization of network connections and, thus, the functional capabilities of a network and the role that nodes (brain regions) play in global and local circuitry (Stam, 2014). For example, the graph theory property Participation Coefficient measures the extent to which a brain region serves as a “hub” that connects different modules (sub-networks). By assessing distributed functional networks, these methods capture greater complexity in the neural bases of psychiatric disorders than is possible when limiting analysis to single regions or even coupling between pairs of regions, approaches that have traditionally dominated research on the neurobiology of psychiatric disorders. This makes graph theory a potentially powerful tool for uncovering large-scale neural circuits that enable the phenotypic complexity inherent in externalizing disorders.
