Differential impact of severity of drug use on frontal behavioral symptoms.

Increasing evidence indicates that substance abusers are impaired in cognitive-executive control tasks relying on different functional systems converging in the prefrontal cortex (PFC). Different PFC functional systems relevant to addiction have been described: the dorsolateral (DLC), orbitofrontal (OFC), and anterior cingulate (ACC) circuits. Each system is associated with different behavioral, cognitive, and emotional deficits, including apathy, disinhibition, and executive dysfunction. In this study, we examined the effects of severity of use of different drugs on apathy, disinhibition and executive dysfunction behavioral deficits as measured by the Frontal Systems Behavior Scale (FrSBe). The FrSBe, and a severity of substance use interview were administered to 32 poly-substance abusers. Multiple regression analyses showed that severity of cannabis use significantly predicted greater apathy and executive dysfunction behavior; and that severity of cocaine use significantly predicted greater disinhibition behavior. These results are consistent with previous studies using cognitive measures and support the notion that severity of substance use significantly affects behavioral symptoms associated with PFC systems functioning. These clinical symptoms should be specifically addressed during rehabilitation.