title: Alcohol and marijuana use in middle school: comparing solitary and social-only users.
abstract: OBJECTIVE
  Middle school students with a history of solitary substance use are at elevated risk for substance problems by young adulthood. Understanding how these students differ from social-only users on substance use behaviors and consequences, normative beliefs, social influences, and attitudes can inform efforts to reduce solitary use and its related negative consequences.
  
  
  METHODS
  Sixth- to seventh-grade students completed an in-school survey. We compared those with a history of solitary versus social-only alcohol use (n = 202 and n = 616, respectively) and marijuana use (n = 92 and n = 208, respectively) on a range of substance use-related characteristics.
  
  
  RESULTS
  Any solitary use was reported by 25% of lifetime alcohol users and 31% of lifetime marijuana users. Those with a history of solitary use of either substance were more likely to hold positive expectancies about their use but also reported more negative consequences during the past year. Solitary users tended to have greater exposure to substance-using peers and more difficulty resisting offers to use. Compared with social-only drinkers, those with a history of solitary drinking perceived that more of their peers were alcohol users. Significant group differences were not found on negative outcome expectancies or attempts to cut down on substance use.
  
  
  CONCLUSIONS
  Solitary use is an important, yet, overlooked problem among middle school students who have just begun drinking or using marijuana. Results suggest that positive expectancies, peer influences, resistance self-efficacy, and normative beliefs may be important areas to target in reducing solitary use and the risk it poses for problematic use in young adulthood.
authors.affiliation: RAND Corporation, Santa Monica, California. Electronic address: jtucker@rand.org.
authors.forename: Joan S
authors.initials: JS
authors.lastname: Tucker
authors.affiliation: RAND Corporation, Santa Monica, California.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Pedersen
authors.affiliation: RAND Corporation, Santa Monica, California.
authors.forename: Jeremy N V
authors.initials: JN
authors.lastname: Miles
authors.affiliation: RAND Corporation, Santa Monica, California.
authors.forename: Brett A
authors.initials: BA
authors.lastname: Ewing
authors.affiliation: RAND Corporation, Arlington, Virginia.
authors.forename: Regina A
authors.initials: RA
authors.lastname: Shih
authors.affiliation: RAND Corporation, Santa Monica, California.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: D'Amico
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000428:Alcohol Drinking / Q000453:epidemiology*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology*; D012919:Social Behavior; D011795:Surveys and Questionnaires
keywords: Alcohol; Marijuana; Middle school; Solitary use