[Research progress on the role of claustrum in substance use disorders]

Substance use disorder (SUD) is characterized by the persistent prioritization of drug-related cues, which readily trigger intense craving and relapse even after prolonged abstinence. Although previous studies have primarily focused on the mesolimbic dopamine system and fronto-striatal circuits, the mechanisms underlying the aberrant integration of reward value, affective states, attentional allocation, and memory representations remain largely elusive. The claustrum-owing to its extensive bidirectional connectivity with both cortical and subcortical networks and its hypothesized role in salience processing-has increasingly been recognized as a key hub in SUD. Accumulating evidence suggests that the claustrum may contribute to drug-cue salience attribution and reward memory encoding, modulate prefrontal information processing and executive control via its reciprocal projections, and interact with limbic systems to sustain withdrawal-related negative affect, thereby influencing relapse vulnerability. Furthermore, emerging findings from psychedelic research indicate that claustrum-related networks are highly plastic and participate in salience reconfiguration. Collectively, the claustrum may act as a cross-network hub that links reward processing, cognitive control, and affective memory, thereby extending classical circuit models of addiction. This review systematically summarizes the structural connectivity, neuroimaging correlates, and functional mechanisms of the claustrum, and discusses its translational implications for relapse prediction and the development of novel intervention strategies.