Chronic drug use is associated with a range of cognitive deficits, including elevated levels of impulsive and risky decision-making, but the causal relationships between these two phenomena have not been clear. Our laboratory uses rodent models to investigate relationships between drug use and decision-making. In one line of research, we have found that chronic cocaine self-administration causes long-lasting increases in impulsive choice in a delay discounting task, and that chronic cocaine exposure results in decreased sensitivity of the task to dopaminergic manipulations. In another line of research, we have developed a risky decision-making task, in which rats choose between small safe rewards and large rewards associated with varying risks of punishment. Preference for the large risky reward is associated with lower D2 dopamine receptor mRNA expression in dorsal striatum, and this preference is reduced by activation of D2-like receptors. Preliminary data also indicate a relationship between greater preference for the large risky reward and acquisition of cocaine self-administration, suggestive of links between risk-taking, drug use, and striatal D2 receptors. Considered together, the data indicate the presence of bi-directional relationships between drug use and decision-making deficits that have the potential to further the process of addiction.
Review Barry Setlow’s biographical statement.