Concurrent validity of the alcohol purchase task in relation to alcohol involvement: protocol for a systematic review and meta-analysis

A neuroeconomic signature of opioid craving: How fluctuations in craving bias drug-related and nondrug-related value

How does craving bias decisions to pursue drugs over other valuable, and healthier, alternatives in addiction? To address this question, we measured the in-the-moment economic decisions of people with opioid use disorder as they experienced craving, shortly after receiving their scheduled opioid maintenance medication and ~24 h later. We found that higher cravers had higher drug-related valuation, and that moments of higher craving within-person also led to higher drug-related valuation. When experiencing increased opioid craving, participants were willing to pay more for personalized consumer items and foods more closely related to their drug use, but not for alternative "nondrug-related" but equally desirable options. This selective increase in value with craving was greater when the drug-related options were offered in higher quantities and was separable from the effects of other fluctuating psychological states like negative mood. These findings suggest that craving narrows and focuses economic motivation toward the object of craving by selectively and multiplicatively amplifying perceived value along a "drug relatedness" dimension.

Concurrent validity of the Alcohol Purchase Task for measuring the reinforcing efficacy of alcohol: an updated systematic review and meta-analysis

BACKGROUND AND AIMS

An early meta-analysis testing the concurrent validity of the Alcohol Purchase Task (APT), a measure of alcohol's relative reinforcing value, reported mixed associations, but predated a large number of studies. This systematic review and meta-analysis sought to: (1) estimate the relationships between trait-based alcohol demand indices from the APT and multiple alcohol indicators, (2) test several moderators and (3) analyze small study effects.

METHODS

A meta-analysis of 50 cross-sectional studies in four databases (n = 18 466, females = 43.32%). Sex, year of publication, number of APT prices and index transformations (logarithmic, square root or none) were considered as moderators. Small study effects were examined by using the Begg-Mazumdar, Egger's and Duval & Tweedie's trim-and-fill tests. Alcohol indicators were quantity of alcohol use, number of heavy drinking episodes, alcohol-related problems and hazardous drinking. APT indices were intensity (i.e. consumption at zero cost), elasticity (i.e. sensitivity to increases in costs), O_max (i.e. maximum expenditure), P_max (i.e. price associated to O_max ) and breakpoint (i.e. price at which consumption ceases).

RESULTS

All alcohol demand indices were significantly associated with all alcohol-related outcomes (r = 0.132-0.494), except P_max , which was significantly associated with alcohol-related problems only (r = 0.064)_. The greatest associations were evinced between intensity in relation to alcohol use, hazardous drinking and heavy drinking and between O_max and alcohol use. All the tested moderators emerged as significant moderators. Evidence of small-study effects was limited.

CONCLUSIONS

The Alcohol Purchase Task appears to have concurrent validity in alcohol research. Intensity and O_max are the most relevant indices to account for alcohol involvement.