Associations of Alcohol, Nicotine, Cannabis, and Drug Use/Dependence with Educational Attainment: Evidence from Cotwin‐Control Analyses

Abstract

Background Although substance use is associated with reduced educational attainment, this association may be due to common risk factors such as socioeconomic disadvantage. We tested whether alcohol, nicotine, and illicit drug use and dependence were associated with lifetime educational attainment after controlling for familial background characteristics. Methods Data were from a 1987 questionnaire and a 1992 telephone diagnostic interview of 6242 male twins (n=3121 pairs; mean age= 41.9 years in 1992) who served in the U.S. military during the Vietnam-era, and therefore were eligible for educational benefits after military service. Reduced educational attainment (less than 16 years) was examined in twin pairs discordant for substance use history. Substance use and dependence risk factors assessed were early alcohol and cannabis use, daily nicotine use, lifetime cannabis use, and alcohol, nicotine, cannabis, and any illicit drug dependence. Results Three significant differences were observed between at risk twins and their cotwins: Compared to their low-risk cotwins, likelihood of completing less than 16 years of education was significantly increased for: (a) twins who used alcohol before age 18 (adjusted OR=1.44; 95%CI:1.02–2.05), (b) twins with a lifetime alcohol dependence diagnosis (adjusted OR=1.76; 95%CI: 1.27–2.44), and (c) twins who had used nicotine daily for 30 or more days (adjusted OR=2.54, 95%CI: 1.55–4.17). However, no differences in education were observed among twin pairs discordant for cannabis initiation, early cannabis use, or cannabis, nicotine, or any illicit drug dependence. Conclusions Even in a veteran population with access to military educational benefits, early alcohol use, alcohol dependence, and daily nicotine use remained significantly associated with years of education after controlling for shared familial contributions to educational attainment. The association between other substances and educational attainment was explained by familial factors common to these substance use phenotypes and adult educational attainment.

Adolescent cannabis and tobacco use and educational outcomes at age 16: birth cohort study

“…Our results are broadly consistent with other evidence suggesting the adverse effect of cannabis use on subsequent educational performance 2, 19, 20, 21, 22, 23. Other studies in general have not considered both cannabis and tobacco use by young people and subsequent educational outcomes in the same cohort; rather, they have reported the effects of cannabis use adjusted for tobacco use.…”

Education, substance use, and HIV risk among orphaned adolescents in Eastern Zimbabwe

“…Although previous work has examined the effect of substance use on educational attainment (Grant et al, 2012; King, Meehan, Trim, & Chassin, 2006; McGue, Iacono, Legrand, Malone, & Elkins, 2001), a review of the literature on the pathways to substance use in adolescents in Canada highlighted academic underachievement and poor attendance as two factors leading to substance use in teenagers (Paglia & Room, 1999), supporting the logic for causation we used herein. Similarly, previous work has also shown that substance use is typically initiated before sexual debut occurs (Tu et al, 2012).…”

High times: The effect of medical marijuana laws on student time use

“…McCaffrey et al (2010) shows that estimates are sensitive to different control variables and propensity score weights, suggesting that unobserved heterogeneity remains an important factor. Moreover, medical research utilizing data on twins finds no causal effects of marijuana use on educational attainment (Grant et al 2012;Bergen et al 2008;Verweij et al 2013). A recent exception to this critique is Marie and Zölitz (2015), who use a difference-indifferences strategy to estimate the effect of a policy that removed college students' legal access to marijuana.…”