The other FC finding was that AUD individuals manifested hyperconnectivity in three connections across five brain regions, i.e., nucleus accumbens, pallidum, hippocampus, posterior cingulate, and dorsolateral prefrontal cortex, possibly suggesting excessive and/or less focused communication during resting state among these structures. While each of these key regions is associated with distinct and shared neurocognitive processes, hyperconnectivity across these nodes during resting state can be generally interpreted as excessive rumination about reward and preoccupation with reward-related imagery or inherent reward-seeking tendencies, such as craving. Similar to our finding, a higher FC between nucleus accumbens and posterior cingulate gyrus was observed in relapsers compared to abstainers of stimulant use [96]. In addition, akin to our finding, higher hippocampal–prefrontal connectivity has also been observed in internet gaming addiction [102]. Furthermore, recent evidence implicating the pallidum as an important structure in mesocorticolimbic reward processing [103], and, therefore, the increased connectivity between pallidum and PCC, may indicate reward related tendencies (e.g., drug seeking) in the resting state. However, despite the growing number of fMRI brain connectivity studies on AUD and other SUDs during resting state
