title: Simultaneous alcohol and cannabis expectancies predict simultaneous use.
abstract: BACKGROUND
  Simultaneous use of alcohol and cannabis predicts increased negative consequences for users beyond individual or even concurrent use of the two drugs. Given the widespread use of the drugs and common simultaneous consumption, problems unique to simultaneous use may bear important implications for many substance users. Cognitive expectancies offer a template for future drug use behavior based on previous drug experiences, accurately predicting future use and problems. Studies reveal similar mechanisms underlying both alcohol and cannabis expectancies, but little research examines simultaneous expectancies for alcohol and cannabis use. Whereas research has demonstrated unique outcomes associated with simultaneous alcohol and cannabis use, this study hypothesized that unique cognitive expectancies may underlie simultaneous alcohol and cannabis use.
  
  
  RESULTS
  This study examined a sample of 2600 (66% male; 34% female) Internet survey respondents solicited through advertisements with online cannabis-related organizations. The study employed known measures of drug use and expectancies, as well as a new measure of simultaneous drug use expectancies. Expectancies for simultaneous use of alcohol and cannabis predicted simultaneous use over and above expectancies for each drug individually.
  
  
  CONCLUSIONS
  Simultaneous expectancies may provide meaningful information not available with individual drug expectancies. These findings bear potential implications on the assessment and treatment of substance abuse problems, as well as researcher conceptualizations of drug expectancies. Policies directing the treatment of substance abuse and its funding ought to give unique consideration to simultaneous drug use and its cognitive underlying factors.
authors.affiliation: VA Greater Los Angeles Healthcare System (GLA), Mail Code 116B, 11301 Wilshire Blvd, Los Angeles, CA 90073, USA. smucker@usc.edu
authors.forename: Sara Smucker
authors.initials: SS
authors.lastname: Barnwell
authors.forename: Mitch
authors.initials: M
authors.lastname: Earleywine
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000523:psychology; D001294:Attitude to Health; D015897:Comorbidity; D055030:Drug Users / Q000706:statistics & numerical data; D005260:Female; D006306:Health Surveys; D006801:Humans; D020407:Internet; D016014:Linear Models; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology* / Q000523:psychology; D008875:Middle Aged; D011237:Predictive Value of Tests; D011581:Psychological Tests / Q000706:statistics & numerical data*; D055815:Young Adult