Study finds racial/ethnic disparities in type of first substance used among U.S. youth; proportion who used marijuana first nearly doubled
A recent study investigated the prevalence of using marijuana before tobacco, alcohol, or other substances among U.S. youth and the outcomes associated with this behavior. Data from respondents aged 12-21 years old (N = 275,559) were obtained from the National Survey on Drug Use and Health (NSDUH) from 2004-2014. Respondents whose age of first drug use could not be determined were excluded from this study (n = 22,073). Outcomes assessed included (1) daily or near daily marijuana use, (2) cannabis use disorder, (3) alcohol use disorder, (4) nicotine dependence, and (5) lifetime use of other drugs. The authors estimated the proportion of respondents who initiated substance use by type of substance and examined variation by demographic characteristics and survey year. Seventeen percent of the sample (n ≈ 43,000) completed follow-up items to measure the aforementioned outcomes. Multinomial logistic regression was used to estimate the degree to which the latter two variables were independently associated with initiating marijuana first, relative to no drug use, cigarettes first, and alcohol first. The authors also explored potential two-way interactions between sex, age, and race/ethnicity. Results indicated the mean age of reported initiation increased for all substances throughout the study period; the mean age of marijuana initiation increased from 14.7 years in 2004 to 15.2 years in 2014. Across all survey years, 5.8% of total respondents reported they initiated marijuana use before other substances, compared to 29.8% for alcohol, 14.2% for cigarettes, 3.6% for other tobacco products, and 5.9% other drugs. During the same period, the proportion who used marijuana first increased from 4.4% to 8.0%, while the proportion who used cigarettes first declined from 21.4% to 8.9% and the proportion who abstained from substance use increased from 35.5% to 46.3%. American Indian/Alaskan Native (AI/AN) (11.8%) and Black youth (9.4%) had the highest proportions of initiating marijuana first; White (4.6%) and Asian youth (2.5%) had the lowest. Compared to Whites, AI/AN youth were 3.7 times more likely to have initiated marijuana first relative to no drug use and were 5.0 times more likely to have initiated marijuana first relative to alcohol. Black youth were the most likely to have initiated marijuana first compared to cigarettes (aRRR = 2.74). The authors found no subgroup interactions by sex, but there was a significant interaction between race/ethnicity and age. Regarding substance use disorders, in general, respondents who first used a particular substance were most likely to have prevalent problematic use of that substance (e.g., those who used marijuana first were most likely to use it at a high frequency and have Cannabis Use Disorder). The authors postulated that the increase in the proportion of youth who reported using marijuana first may be due to a decline in cigarette use initiation, changes in state marijuana laws (increased access to marijuana), and increased acceptability of marijuana use.
Take away: The proportion of youth who reported the first drug they ever used was marijuana nearly doubled between 2004 and 2014 (from 4% to 8%). American Indian/Alaskan Native and Black youth had the highest proportions of using marijuana first, although there was less variation across racial/ethnic groups as participants’ ages increased.
Fairman, B.J., Furr-Holden, C.D. & Johnson, R.M. (2018). When marijuana is used before cigarettes or alcohol: Demographic predictors and associations with heavy use, Cannabis Use Disorder, and other drug-related outcomes. Prevention Science [published online ahead of print May 17, 2018] doi: 10.1007/s11121-018-0908-3