Altered subjective reward valuation among drug-deprived heavy marijuana users: Aversion to uncertainty.

Abstract

Marijuana is the most commonly used illicit drug in the United States and its use is rising. Nonetheless, scientific efforts to clarify the risk for addiction and other harm associated with marijuana use have been lacking. Maladaptive decision-making is a cardinal feature of addiction that is likely to emerge in heavy users. In particular, distorted subjective reward valuation related to homeostatic or allostatic processes has been implicated for many drugs of abuse. Selective changes in responses to uncertainty have been observed in response to intoxication and deprivation from various drugs of abuse. To assess for these potential neuroadaptive changes in reward valuation associated with marijuana deprivation, we examined the subjective value of uncertain and certain rewards among deprived and non-deprived heavy marijuana users in a behavioral economics decision-making task. Deprived users displayed reduced valuation of uncertain rewards, particularly when these rewards were more objectively valuable. This uncertainty aversion increased with increasing quantity of marijuana use. These results suggest comparable decision-making vulnerability from marijuana use as other drugs of abuse, and highlights targets for intervention.

Association between problematic alcohol use and reactivity to uncertain threat in two independent samples

“…For instance, Hogle et al (2010) have demonstrated that within smokers, nicotine deprivation selectively increases startle potentiation to an unpredictable threat and that both anticipating smoking a cigarette and actually smoking a cigarette significantly dampens this reactivity (Bradford et al, 2015). Meanwhile, heavy marijuana users have been shown to exhibit heightened aversive reactivity to an uncertain threat and an uncertain reward (Hefner et al, 2015; Gloria et al, 2015, in preparation), highlighting the possibility that substance users evidence a broad sensitivity to uncertainty and find unpredictable threats and rewards aversive. Taken together, reactivity to uncertainty, particularly an uncertain threat, has emerged as an important construct related to several forms of substance use and future studies should therefore continue to clarify its role in substance use initiation, maintenance and relapse.…”

The effects of alcohol on emotion in social drinkers

“…Moreover, they identified potential individual-difference factors (e.g., binge drinking history, negative emotionality) that may moderate alcohol’s anxiolytic effects (Bradford et al, 2013; Hefner et al, 2013). Another feature of this research program is the degree to which the mechanisms of stimulus certainty or predictability have been contrasted across drugs of abuse (Hefner, Starr, & Curtin, 2016; Hogle, Kaye, & Curtin, 2010). The appeal of the shock threat paradigm is that there is more control over factors such as predictability than one would expect using more unwieldy social interaction manipulations.…”

Intolerance of uncertainty and insula activation during uncertain reward

“…For instance, subsequent studies should consider tasks that allow for a comparison of neural reactivity during the anticipation of unpredictable rewards relative to predictable rewards (Alkozei, Smith, & Killgore, 2016), which could involve manipulations of reward timing, probability, and/or amount. Second, to better simulate dynamics of the real world, studies could also consider tasks that manipulate rewards (or threats) in such a way that participants are able to learn various contingencies, make decisions regarding the potential for reward, and then use these estimates to inform their behavioral response (e.g., Hefner, Starr, & Curtin, 2015;Hsu, Bhatt, Adolphs, Tranel, & Camerer, 2005). This would ultimately allow for real-time assessments of aversion/preference for uncertainty and its impact on behavior.…”