title: 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 nondeprived 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.
authors.affiliation: Mental Illness Research, Education, and Clinical Centers (MIRECC), VA Connecticut Healthcare System.
authors.forename: Kathryn R
authors.initials: KR
authors.lastname: Hefner
authors.affiliation: Department of Psychology, University of Wisconsin-Madison.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Starr
authors.affiliation: Department of Psychology, University of Wisconsin-Madison.
authors.forename: John J
authors.initials: JJ
authors.lastname: Curtin
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect / Q000502:physiology; D003657:Decision Making / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000523:psychology*; D008385:Marijuana Smoking / Q000523:psychology*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D035501:Uncertainty; D055815:Young Adult