PROJECT MOST
Founded in 2015 by Matthew R. Pearson, the Marijuana Outcomes Study Team (MOST) is a collective of scientists in the behavioral sciences with a shared vision of answering meaningful research questions regarding marijuana use that have important policy, prevention, and/or treatment implications.
The first project conducted by the Marijuana Outcomes Study Team was Project Most. In this online survey study, we recruited >8,000 college students from 11 universities starting in Fall 2015 and ending in Spring 2016 (see coverage map below).
We examined a wide range of factors expected to be related to marijuana-related outcomes. Currently, we have 10 publications using Project Most data with more under way. If you would like to receive any or all of these publications, please email the coordinating principal investigator at mateo.pearson@gmail.com. We have provided brief descriptions of these projects below.
If you would like to know more about the assessment battery, go here.
We are also doing a limited release of Project Most data to qualified researchers. If you would like to obtain Project Most data, please fill out this form and email it to the coordinating principal investigator at mateo.pearson@gmail.com.
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For the most detailed description of the project and basic descriptives for our sample, see:
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Rather than considering marijuana users as a homogeneous group, we used latent profile analysis to identify distinct subgroups of marijuana users that differed in marijuana use frequency and experience of consequences. The most salient risk factor was identification with being a marijuana user and the most salient protective factor was use of protective behavioral strategies.
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We developed a measure to assess the degree to which college students perceive marijuana to be an essential part of the college experience (PIMCES) and found that it was robustly associated with marijuana-related outcomes.
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We found that use of protective behavioral strategies at least partially mediated the effects of a wide range of distal antecedents on marijuana-related outcomes (use/consequences).
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We also found that use of protective behavioral strategies buffered the effects of certain risk factors and enhanced the effects of certain protective factors on marijuana-related outcomes.
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We used item response theory to develop a short, 17-item version of the Protective Behavioral Strategies for Marijuana Scale (PBSM) that is free of bias in terms of gender, race, ethnicity, and state legal status of marijuana.
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We found that marijuana-related norms (descriptive norms, injunctive norms, and internalized norms) largely mediated the effects of personality on marijuana-related outcomes, extending findings in the alcohol literature.
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Using recursive partitioning, we found that norms (descriptive, injunctive, and internalized norms) and marijuana identity best distinguished marijuana users from nonusers, whereas marijuana use frequency, use of protective behavioral strategies, and positive/negative urgency best distinguished the degree to which users reported negative consequences.
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We found a curvilinear relation between sexual orientation and consequences among men, but not among women, such that bisexual men report more consequences that exclusively hetero- or homosexual men, at least partially due to lower PBS use.
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We found that use of protective behavioral strategies mediates the associations between two facets of sensation seeking (experience seeking and risk seeking) on marijuana-related negative consequences.
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For Project Most, the Marijuana Outcomes Study Team included the following investigators (in alphabetical order):
Amber M. Anthenien (University of Houston), Adrian J. Bravo (University of New Mexico), Bradley T. Conner (Colorado State University), Christopher J. Correia (Auburn University), Robert D. Dvorak (University of Central Florida), Gregory A. Egerton (University at Buffalo), John T. P. Hustad (Pennsylvania State University), Tatyana Kholodkov (University of Wyoming), Bruce S. Liese (University of Kansas), Kevin M. King (University of Washington), Bryan G. Messina (Auburn University), James G. Murphy (The University of Memphis), Clayton Neighbors (University of Houston), Xuan-Thanh Nguyen (University of California, Los Angeles), Jamie E. Parnes (Colorado State University), Eric R. Pedersen (RAND), Mark A. Prince (Colorado State University), Matthew R. Pearson (University of New Mexico), Sharon A. Radomski (University at Buffalo), Lara A. Ray (University of California, Los Angeles), Jennifer P. Read (University at Buffalo)
PROJECT MOST 2.0
The second project conducted by the Marijuana Outcomes Study Team was Project Most 2.0 (creative, huh?). In this online survey study, we recruited 7,000 college students from 9 universities starting in Fall 2016 and ending in Spring 2017 (see coverage map below).
To date, we have not yet published findings from this study, but several manuscripts are under review or in preparation.
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For Project Most 2.0, the Marijuana Outcomes Study Team included the following principal investigators (in alphabetical order):
Adrian J. Bravo (University of New Mexico), Bradley T. Conner (Colorado State University), Robert D. Dvorak (University of Central Florida), James M. Henson (Old Dominion University), John T. P. Hustad (Pennsylvania State University), Bruce S. Liese (University of Kansas), Kevin M. King (University of Washington), James G. Murphy (The University of Memphis), Clayton Neighbors (University of Houston), Eric R. Pedersen (RAND), Mark A. Prince (Colorado State University), Matthew R. Pearson (University of New Mexico), Lara A. Ray (University of California, Los Angeles), Jennifer P. Read (University at Buffalo)