There is some debate over whether disinhibition is a cause or a consequence of substance use. There are two possible explanations, which are not mutually exclusive: (i) chronic heavy substance use may increase disinhibition through neurotoxic effects in the prefrontal cortex, and (ii) children and adolescents who are particularly disinhibited are at increased risk of initiating substance use and developing substance use disorders. In support of the first explanation, it is well-established that chronic alcoholics present with structural brain damage, with prefrontal areas showing the greatest damage associated with heavy drinking (22, 23). These prefrontal regions are implicated in executive functions, including disinhibition, so structural and functional damage here should correspond to disinhibited behavior (24–26). Furthermore, animal research reveals that chronic alcohol administration and/or binge cycles causes structural and functional damage to the brain (27–29).
