Left/right hemispheric “unbalance” model in addiction

Addiction is a complex phenomenon involving genetic, neurobiological, and environmental factors. Neuroscience literature has shown several functional and structural changes in the addict's brain, in particular alterations in the neural circuits of the limbic system (related to reward-related systems) and the prefrontal cortex (for the higher cognitive functions). This anomalous brain activity could explain impairments in emotional and cognitive processes involved in decision-making and rewarding bias, thus addicts are vulnerable to relapse and persist with dysfunctional behavior. We focus on the main research on addiction disease that elucidated the neurophysiological mechanisms (brain oscillations and connectivity) implicated, and propose a model, namely Integrative Cortical Unbalance Model that includes the relationship among the motivational system (behavioral activation system), the reward sensitivity bias, and the left lateralization unbalance effect. Finally, we discuss some novel lines of treatment to improve both clinical phenomenology and metacognitive strategies in addiction.