Incentive salience is a multidimensional construct that includes craving, drug value relative to other reinforcers, and implicit motivation such as attentional bias to drug cues. Laboratory cue reactivity (CR) paradigms have been used to evaluate marijuana incentive salience with measures of craving, but not with behavioral economic measures of marijuana demand or implicit attentional processing tasks.
[Photo: Dr. Jane Metrik]
This within-subjects study by Dr. Jane Metrik, assistant professor of behavioral and social sciences in the Brown University School of Public Health and colleagues, used a new CR paradigm to examine multiple dimensions of marijuana’s incentive salience and to compare CR-induced increases in craving and demand. Frequent marijuana users underwent exposure to neutral cues then to lit marijuana cigarettes. Craving, marijuana demand via a marijuana purchase task, and heart rate were assessed after each cue set. A modified Stroop task with cannabis and control words was completed after the marijuana cues as a measure of attentional bias.
Relative to neutral cues, marijuana cues significantly increased subjective craving and demand indices of intensity and Omax. Elasticity significantly decreased following marijuana cues, reflecting sustained purchase despite price increases. Craving was correlated with demand indices. Marijuana users displayed significant attentional bias for cannabis-related words after marijuana cues. Cue-elicited increases in intensity were associated with greater attentional bias for marijuana words.
Greater incentive salience indexed by subjective, behavioral economic, and implicit measures was observed after marijuana versus neutral cues, supporting multidimensional assessment. This study highlights the utility of a behavioral economic approach in detecting cue-elicited changes in marijuana incentive salience.
This study was published in Drug and Alcohol Dependence, August 2016.