Addiction is a neurobiological disorder in which repeated drug use reorganizes the neural pathways that mediate reward and adaptive behaviors, causing neuroplastic changes. Such changes are manipulated through compulsive drug-seeking behaviors, inability to control such behaviors, continued use of substances, despite negative consequences, vulnerability to relapse, even after a long period of withdrawal, reduced need for biologically relevant and fundamental natural rewards for survival (Kalivas and O’Brien, 2008; Koob and Volkow, 2010; Feltenstein et al., 2020).
At the level of neuronal circuitry, it has been shown that drugs of abuse cause changes in several brain areas, especially those involved in the reward system, such as the striatum, the basal ganglia, the limbic system and the prefrontal cortex. Thus, for example, the striatum would be associated with reward-associated learning (Gerfen and Surmeier, 2011; Kim et al., 2017). Likewise, most of the drugs of abuse stimulate the release of dopamine in the mesoaccumbens dopaminergic system, which is responsible for modulating the reinforcing effects of these drugs (Alcaro et al., 2007).