As we predicted, the AUD group showed increased connections in the anterior SN, especially the FC between the left insula and ACC, SMA, and mPFC. The insula and ACC are key nodes in the SN, which separates the most relevant internal and extra-personal stimuli for guiding goal-directed behavior. In particular, the FCs between these regions facilitate rapid access to the motor system (13, 16, 19). According to the neuro-circuitry model of addiction (12, 41, 42), enhanced interactions between the insula and ACC may be related to elevated salience for addictive substance and related cues at the expense of other activities. As a result, the disrupted ACC–insula circuits may render individuals with AUD vulnerable to engaging with alcohol consumption.
