Neurocognitive and Personality Mechanisms of Risk Behavior among Drug Users in Protracted Abstinence
thesisposted on 18.10.2016 by Michael J. Wilson
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The current study examined relationships between candidate personality and neurocognitive mechanisms of health risk behaviors among demographically representative samples of opiate and stimulant dependent individuals in protracted abstinence. Specific hypotheses were evaluated regarding the nature and directionality of associations between externalizing personality traits (i.e. Trait Impulsivity; Sensation-Seeking; Psychopathy), neurocognitive dimensions of impulsivity (i.e Impulsive Action; Impulsive Choice), and risk behaviors (i.e. risky sexual practices; injection drug use; aggression; problem gambling). The predicted moderating effects of prior dependence on specific pharmacologic classes of drugs (i.e. amphetamines; heroin; polysubstance) on relationships between these constructs were also evaluated, as were the potential mediating effects of neurocognitive impulsivity on associations between externalizing personality traits and risk behaviors. Results indicated that Psychopathy was the most robust and consistent predictor of risk behavior across all drug users. Different dimensions of the externalizing spectrum were found to correlate with specific neurocognitive impulsivity profiles, such that Trait Impulsivity was linked primarily to Impulsive Action, Psychopathy was linked to disadvantageous reward-based decision-making under conditions of cognitive complexity (Impulsive Choice), and Sensation-Seeking was linked to advantageous reward-based decision-making under explicit risk conditions and disadvantageous reward-based decision-making under ambiguity. Sexual risk behavior in protracted abstinence was linked to poor decision-making under ambiguity in the context of cognitive complexity (Impulsive Choice), while aggression and problem gambling were linked to Impulsive Action. Hypotheses that Psychopathy would be most strongly associated with risk behaviors among former heroin users were largely confirmed. By contrast, hypotheses that Trait Impulsivity and Sensation-Seeking would be most strongly associated with risk behaviors among former amphetamine users were largely disconfirmed, indicating that protracted abstinence may change the personality-risk behavior profile associated with amphetamine dependence but not heroin dependence. Contrary to predictions, neurocognitive impulsivity did not mediate associations of externalizing personality traits with risk behaviors, likely owing to amelioration of cognitive deficits with maintained abstinence.