Altered risk-related processing in substance users: imbalance of pain and gain

Abstract

Background: Substance use disorders (SUDs) can be conceptualized as a form of risk-taking behavior with the potential for highly aversive outcomes such as health or legal problems. Risky decision-making likely draws upon several related brain processes involved in estimations of value and risk, executive control, and emotional processing. SUDs may result from a dysfunction in one or more of these cognitive processes.

Methods: We performed a systematic literature review of functional neuroimaging studies examining risk-related decision making in individuals with SUDs. A quantitative meta-analysis tool (GingerALE) and qualitative approach was used to summarize the imaging results.

Results: Meta-analysis findings indicate that individuals with SUDs exhibit differences in neural activity relative to healthy controls during risk-taking in the anterior cingulate cortex, orbitofrontal cortex, dorsolateral prefrontal cortex, striatum, insula, and somatosensory cortex. In addition, a qualitative review of the literature suggests that individuals with SUDs may have altered function in the amygdala and ventromedial prefrontal cortex.

Conclusions: The neuroimaging literature reveals that several neural substrates involved in the computation of risk may function suboptimally in SUDs. Future research is warranted to elucidate which computational processes are affected, whether dysfunctional risk-related processing recovers with sobriety, and whether different drugs of abuse have specific effects on risk-taking.

Keywords: Addiction; Decision-making; Drug abuse; Neuroimaging; Risk-taking.

Figure 1

Hypothetical model of risk processing in SUD brain. Ventromedial prefrontal cortex (VMPFC), orbitofrontal cortex (OFC) and striatum contribute to the subjective evaluation of options and play an enhanced role in risk-taking decisions for individuals with SUDs. The rest of the regions in the model play a diminished role in risk-taking decisions for individuals with SUDs. Anterior cingulate cortex (ACC) and insula are involved in processing risk magnitude and probability. The insula, in conjunction with the primary somatosensory cortex, also contributes to assessment of body state. The amygdala contributes emotional evaluation of options. Finally, dorsolateral prefrontal cortex (DLPFC) is involved in executive control, possibly integrating information from risk and reward evaluation.