Divergent neural mechanisms of reward processing and cognitive control in non-substance and substance addiction: A meta-analytic perspective

Addiction disorders, encompassing non-substance and substance addiction, are a prevalent and devastating class of mental illnesses. The dual-system theory of addiction posits that abnormal processing in the brain's reward and control systems underlies addictive behaviors. However, challenges in previous neuroimaging studies on addiction, including small sample sizes, subjective narrative reviews, and inconsistent findings, have limited the comprehensive clarification of the neural mechanisms underlying addiction. This meta-analysis addresses these limitations by integrating neuroimaging data from multiple studies. Here, the random-effects activation likelihood estimation (ALE) method was applied to systematically synthesize data to elucidate the neural mechanisms of reward processing and cognitive control in non-substance and substance addiction. The study revealed that individuals with non-substance addiction presented increased dorsal anterior cingulate cortex (dACC) and caudate activation during cue reactivity, enhanced putamen and globus pallidus responses to non-specific rewards, and no significant group differences in cognitive control tasks. In contrast, substance addiction was found to be characterized by heightened activation in the rostral anterior cingulate cortex (rACC), ventromedial prefrontal cortex (vmPFC) and putamen during cue reactivity, accompanied by reduced responses of the nucleus accumbens (NAc) to non-specific rewards and reduced activation in the inferior parietal lobule (IPL) during cognitive-control tasks. These findings not only reveal a potential "motivation-control equilibrium" mechanism in non-substance addiction but also support the dual-system framework for substance addiction, providing neurobiological targets for precision interventions.